diff --git a/scwx-qt/source/scwx/qt/gl/draw/geo_lines.cpp b/scwx-qt/source/scwx/qt/gl/draw/geo_lines.cpp
index 7f05aaaf..bcf6214b 100644
--- a/scwx-qt/source/scwx/qt/gl/draw/geo_lines.cpp
+++ b/scwx-qt/source/scwx/qt/gl/draw/geo_lines.cpp
@@ -1,11 +1,12 @@
 #include <scwx/qt/gl/draw/geo_lines.hpp>
 #include <scwx/qt/util/geographic_lib.hpp>
-#include <scwx/qt/util/texture_atlas.hpp>
-#include <scwx/common/geographic.hpp>
+#include <scwx/qt/util/maplibre.hpp>
+#include <scwx/qt/util/tooltip.hpp>
 #include <scwx/util/logger.hpp>
 
-#include <numbers>
-#include <optional>
+#include <execution>
+
+#include <units/angle.h>
 
 namespace scwx
 {
@@ -23,29 +24,53 @@ static constexpr size_t kNumRectangles        = 1;
 static constexpr size_t kNumTriangles         = kNumRectangles * 2;
 static constexpr size_t kVerticesPerTriangle  = 3;
 static constexpr size_t kVerticesPerRectangle = kVerticesPerTriangle * 2;
-static constexpr size_t kPointsPerVertex      = 11;
+static constexpr size_t kPointsPerVertex      = 9;
 static constexpr size_t kBufferLength =
    kNumTriangles * kVerticesPerTriangle * kPointsPerVertex;
 
-static const std::string kTextureName = "lines/default-1x7";
+// Threshold, start time, end time
+static constexpr std::size_t kIntegersPerVertex_ = 3;
+
+struct GeoLineDrawItem
+{
+   bool                                        visible_ {true};
+   units::length::nautical_miles<double>       threshold_ {};
+   std::chrono::sys_time<std::chrono::seconds> startTime_ {};
+   std::chrono::sys_time<std::chrono::seconds> endTime_ {};
+
+   boost::gil::rgba32f_pixel_t  modulate_ {1.0f, 1.0f, 1.0f, 1.0f};
+   float                        latitude1_ {};
+   float                        longitude1_ {};
+   float                        latitude2_ {};
+   float                        longitude2_ {};
+   float                        width_ {5.0};
+   units::angle::degrees<float> angle_ {};
+   std::string                  hoverText_ {};
+};
 
 class GeoLines::Impl
 {
 public:
+   struct LineHoverEntry
+   {
+      std::shared_ptr<const GeoLineDrawItem> di_;
+
+      glm::vec2 p1_;
+      glm::vec2 p2_;
+      glm::vec2 otl_;
+      glm::vec2 otr_;
+      glm::vec2 obl_;
+      glm::vec2 obr_;
+   };
+
    explicit Impl(std::shared_ptr<GlContext> context) :
        context_ {context},
-       geodesic_ {util::GeographicLib::DefaultGeodesic()},
-       dirty_ {false},
-       visible_ {true},
-       points_ {},
-       angle_ {},
-       width_ {7.0f},
-       modulateColor_ {std::nullopt},
        shaderProgram_ {nullptr},
        uMVPMatrixLocation_(GL_INVALID_INDEX),
        uMapMatrixLocation_(GL_INVALID_INDEX),
        uMapScreenCoordLocation_(GL_INVALID_INDEX),
-       texture_ {},
+       uMapDistanceLocation_(GL_INVALID_INDEX),
+       uSelectedTimeLocation_(GL_INVALID_INDEX),
        vao_ {GL_INVALID_INDEX},
        vbo_ {GL_INVALID_INDEX}
    {
@@ -53,30 +78,40 @@ public:
 
    ~Impl() {}
 
+   void BufferLine(const std::shared_ptr<const GeoLineDrawItem>& di);
+   void Update();
+   void UpdateBuffers();
+
    std::shared_ptr<GlContext> context_;
 
-   const GeographicLib::Geodesic& geodesic_;
+   bool visible_ {true};
+   bool dirty_ {false};
+   bool thresholded_ {false};
 
-   bool dirty_;
+   std::chrono::system_clock::time_point selectedTime_ {};
 
-   bool                              visible_;
-   std::array<common::Coordinate, 2> points_;
-   float                             angle_;
-   float                             width_;
+   std::mutex lineMutex_ {};
 
-   std::optional<boost::gil::rgba8_pixel_t> modulateColor_;
+   std::vector<std::shared_ptr<GeoLineDrawItem>> currentLineList_ {};
+   std::vector<std::shared_ptr<GeoLineDrawItem>> newLineList_ {};
+
+   std::vector<float> currentLinesBuffer_ {};
+   std::vector<GLint> currentIntegerBuffer_ {};
+   std::vector<float> newLinesBuffer_ {};
+   std::vector<GLint> newIntegerBuffer_ {};
+
+   std::vector<LineHoverEntry> currentHoverLines_ {};
+   std::vector<LineHoverEntry> newHoverLines_ {};
 
    std::shared_ptr<ShaderProgram> shaderProgram_;
    GLint                          uMVPMatrixLocation_;
    GLint                          uMapMatrixLocation_;
    GLint                          uMapScreenCoordLocation_;
+   GLint                          uMapDistanceLocation_;
+   GLint                          uSelectedTimeLocation_;
 
-   util::TextureAttributes texture_;
-
-   GLuint vao_;
-   GLuint vbo_;
-
-   void Update();
+   GLuint                vao_;
+   std::array<GLuint, 2> vbo_;
 };
 
 GeoLines::GeoLines(std::shared_ptr<GlContext> context) :
@@ -93,37 +128,24 @@ void GeoLines::Initialize()
    gl::OpenGLFunctions& gl = p->context_->gl();
 
    p->shaderProgram_ = p->context_->GetShaderProgram(
-      ":/gl/geo_line.vert", ":/gl/texture2d_array.frag");
-
-   p->uMVPMatrixLocation_ =
-      gl.glGetUniformLocation(p->shaderProgram_->id(), "uMVPMatrix");
-   if (p->uMVPMatrixLocation_ == -1)
-   {
-      logger_->warn("Could not find uMVPMatrix");
-   }
-
-   p->uMapMatrixLocation_ =
-      gl.glGetUniformLocation(p->shaderProgram_->id(), "uMapMatrix");
-   if (p->uMapMatrixLocation_ == -1)
-   {
-      logger_->warn("Could not find uMapMatrix");
-   }
+      {{GL_VERTEX_SHADER, ":/gl/geo_texture2d.vert"},
+       {GL_GEOMETRY_SHADER, ":/gl/threshold.geom"},
+       {GL_FRAGMENT_SHADER, ":/gl/color.frag"}});
 
+   p->uMVPMatrixLocation_ = p->shaderProgram_->GetUniformLocation("uMVPMatrix");
+   p->uMapMatrixLocation_ = p->shaderProgram_->GetUniformLocation("uMapMatrix");
    p->uMapScreenCoordLocation_ =
-      gl.glGetUniformLocation(p->shaderProgram_->id(), "uMapScreenCoord");
-   if (p->uMapScreenCoordLocation_ == -1)
-   {
-      logger_->warn("Could not find uMapScreenCoord");
-   }
-
-   p->texture_ =
-      util::TextureAtlas::Instance().GetTextureAttributes(kTextureName);
+      p->shaderProgram_->GetUniformLocation("uMapScreenCoord");
+   p->uMapDistanceLocation_ =
+      p->shaderProgram_->GetUniformLocation("uMapDistance");
+   p->uSelectedTimeLocation_ =
+      p->shaderProgram_->GetUniformLocation("uSelectedTime");
 
    gl.glGenVertexArrays(1, &p->vao_);
-   gl.glGenBuffers(1, &p->vbo_);
+   gl.glGenBuffers(static_cast<GLsizei>(p->vbo_.size()), p->vbo_.data());
 
    gl.glBindVertexArray(p->vao_);
-   gl.glBindBuffer(GL_ARRAY_BUFFER, p->vbo_);
+   gl.glBindBuffer(GL_ARRAY_BUFFER, p->vbo_[0]);
    gl.glBufferData(
       GL_ARRAY_BUFFER, sizeof(float) * kBufferLength, nullptr, GL_DYNAMIC_DRAW);
 
@@ -145,44 +167,96 @@ void GeoLines::Initialize()
                             reinterpret_cast<void*>(2 * sizeof(float)));
    gl.glEnableVertexAttribArray(1);
 
-   // aTexCoord
-   gl.glVertexAttribPointer(2,
-                            3,
-                            GL_FLOAT,
-                            GL_FALSE,
-                            kPointsPerVertex * sizeof(float),
-                            reinterpret_cast<void*>(4 * sizeof(float)));
-   gl.glEnableVertexAttribArray(2);
-
    // aModulate
    gl.glVertexAttribPointer(3,
                             4,
                             GL_FLOAT,
                             GL_FALSE,
                             kPointsPerVertex * sizeof(float),
-                            reinterpret_cast<void*>(7 * sizeof(float)));
+                            reinterpret_cast<void*>(4 * sizeof(float)));
    gl.glEnableVertexAttribArray(3);
 
+   // aAngle
+   gl.glVertexAttribPointer(4,
+                            1,
+                            GL_FLOAT,
+                            GL_FALSE,
+                            kPointsPerVertex * sizeof(float),
+                            reinterpret_cast<void*>(8 * sizeof(float)));
+   gl.glEnableVertexAttribArray(4);
+
+   gl.glBindBuffer(GL_ARRAY_BUFFER, p->vbo_[1]);
+   gl.glBufferData(GL_ARRAY_BUFFER, 0u, nullptr, GL_DYNAMIC_DRAW);
+
+   // aThreshold
+   gl.glVertexAttribIPointer(5, //
+                             1,
+                             GL_INT,
+                             kIntegersPerVertex_ * sizeof(GLint),
+                             static_cast<void*>(0));
+   gl.glEnableVertexAttribArray(5);
+
+   // aTimeRange
+   gl.glVertexAttribIPointer(6, //
+                             2,
+                             GL_INT,
+                             kIntegersPerVertex_ * sizeof(GLint),
+                             reinterpret_cast<void*>(1 * sizeof(GLint)));
+   gl.glEnableVertexAttribArray(6);
+
    p->dirty_ = true;
 }
 
 void GeoLines::Render(const QMapLibreGL::CustomLayerRenderParameters& params)
 {
-   if (p->visible_)
+   if (!p->visible_)
+   {
+      return;
+   }
+
+   std::unique_lock lock {p->lineMutex_};
+
+   if (p->currentLineList_.size() > 0)
    {
       gl::OpenGLFunctions& gl = p->context_->gl();
 
       gl.glBindVertexArray(p->vao_);
-      gl.glBindBuffer(GL_ARRAY_BUFFER, p->vbo_);
 
       p->Update();
       p->shaderProgram_->Use();
-      UseDefaultProjection(params, p->uMVPMatrixLocation_);
+      UseRotationProjection(params, p->uMVPMatrixLocation_);
       UseMapProjection(
          params, p->uMapMatrixLocation_, p->uMapScreenCoordLocation_);
 
-      // Draw line
-      gl.glDrawArrays(GL_TRIANGLES, 0, 6);
+      if (p->thresholded_)
+      {
+         // If thresholding is enabled, set the map distance
+         units::length::nautical_miles<float> mapDistance =
+            util::maplibre::GetMapDistance(params);
+         gl.glUniform1f(p->uMapDistanceLocation_, mapDistance.value());
+      }
+      else
+      {
+         // If thresholding is disabled, set the map distance to 0
+         gl.glUniform1f(p->uMapDistanceLocation_, 0.0f);
+      }
+
+      // Selected time
+      std::chrono::system_clock::time_point selectedTime =
+         (p->selectedTime_ == std::chrono::system_clock::time_point {}) ?
+            std::chrono::system_clock::now() :
+            p->selectedTime_;
+      gl.glUniform1i(
+         p->uSelectedTimeLocation_,
+         static_cast<GLint>(std::chrono::duration_cast<std::chrono::minutes>(
+                               selectedTime.time_since_epoch())
+                               .count()));
+
+      // Draw icons
+      gl.glDrawArrays(GL_TRIANGLES,
+                      0,
+                      static_cast<GLsizei>(p->currentLineList_.size() *
+                                           kVerticesPerRectangle));
    }
 }
 
@@ -191,52 +265,13 @@ void GeoLines::Deinitialize()
    gl::OpenGLFunctions& gl = p->context_->gl();
 
    gl.glDeleteVertexArrays(1, &p->vao_);
-   gl.glDeleteBuffers(1, &p->vbo_);
-}
+   gl.glDeleteBuffers(2, p->vbo_.data());
 
-void GeoLines::SetPoints(float latitude1,
-                         float longitude1,
-                         float latitude2,
-                         float longitude2)
-{
-   if (p->points_[0].latitude_ != latitude1 ||
-       p->points_[0].longitude_ != longitude1 ||
-       p->points_[1].latitude_ != latitude2 ||
-       p->points_[1].longitude_ != longitude2)
-   {
-      p->points_[0] = {latitude1, longitude1};
-      p->points_[1] = {latitude2, longitude2};
+   std::unique_lock lock {p->lineMutex_};
 
-      double azi1; // Azimuth at point 1 (degrees)
-      double azi2; // (Forward) azimuth at point 2 (degrees)
-      p->geodesic_.Inverse(p->points_[0].latitude_,
-                           p->points_[0].longitude_,
-                           p->points_[1].latitude_,
-                           p->points_[1].longitude_,
-                           azi1,
-                           azi2);
-      p->angle_ = -azi1 * std::numbers::pi / 180.0;
-
-      p->dirty_ = true;
-   }
-}
-
-void GeoLines::SetModulateColor(boost::gil::rgba8_pixel_t color)
-{
-   if (p->modulateColor_ != color)
-   {
-      p->modulateColor_ = color;
-      p->dirty_         = true;
-   }
-}
-
-void GeoLines::SetWidth(float width)
-{
-   if (p->width_ != width)
-   {
-      p->width_ = width;
-      p->dirty_ = true;
-   }
+   p->currentLinesBuffer_.clear();
+   p->currentIntegerBuffer_.clear();
+   p->currentHoverLines_.clear();
 }
 
 void GeoLines::SetVisible(bool visible)
@@ -244,68 +279,328 @@ void GeoLines::SetVisible(bool visible)
    p->visible_ = visible;
 }
 
+void GeoLines::StartLines()
+{
+   // Clear the new buffers
+   p->newLineList_.clear();
+   p->newLinesBuffer_.clear();
+   p->newIntegerBuffer_.clear();
+   p->newHoverLines_.clear();
+}
+
+std::shared_ptr<GeoLineDrawItem> GeoLines::AddLine()
+{
+   return p->newLineList_.emplace_back(std::make_shared<GeoLineDrawItem>());
+}
+
+void GeoLines::SetLineLocation(const std::shared_ptr<GeoLineDrawItem>& di,
+                               float latitude1,
+                               float longitude1,
+                               float latitude2,
+                               float longitude2)
+{
+   di->latitude1_  = latitude1;
+   di->longitude1_ = longitude1;
+   di->latitude2_  = latitude2;
+   di->longitude2_ = longitude2;
+}
+
+void GeoLines::SetLineModulate(const std::shared_ptr<GeoLineDrawItem>& di,
+                               boost::gil::rgba8_pixel_t               modulate)
+{
+   di->modulate_ = {modulate[0] / 255.0f,
+                    modulate[1] / 255.0f,
+                    modulate[2] / 255.0f,
+                    modulate[3] / 255.0f};
+}
+
+void GeoLines::SetLineModulate(const std::shared_ptr<GeoLineDrawItem>& di,
+                               boost::gil::rgba32f_pixel_t             modulate)
+{
+   di->modulate_ = modulate;
+}
+
+void GeoLines::SetLineWidth(const std::shared_ptr<GeoLineDrawItem>& di,
+                            float                                   width)
+{
+   di->width_ = width;
+}
+
+void GeoLines::SetLineVisible(const std::shared_ptr<GeoLineDrawItem>& di,
+                              bool                                    visible)
+{
+   di->visible_ = visible;
+}
+
+void GeoLines::SetLineHoverText(const std::shared_ptr<GeoLineDrawItem>& di,
+                                const std::string&                      text)
+{
+   di->hoverText_ = text;
+}
+
+void GeoLines::FinishLines()
+{
+   // Update buffers
+   p->UpdateBuffers();
+
+   std::unique_lock lock {p->lineMutex_};
+
+   // Swap buffers
+   p->currentLineList_.swap(p->newLineList_);
+   p->currentLinesBuffer_.swap(p->newLinesBuffer_);
+   p->currentIntegerBuffer_.swap(p->newIntegerBuffer_);
+   p->currentHoverLines_.swap(p->newHoverLines_);
+
+   // Clear the new buffers, except the full line list (used to update buffers
+   // without re-adding lines)
+   p->newLinesBuffer_.clear();
+   p->newIntegerBuffer_.clear();
+   p->newHoverLines_.clear();
+
+   // Mark the draw item dirty
+   p->dirty_ = true;
+}
+
+void GeoLines::Impl::UpdateBuffers()
+{
+   newLinesBuffer_.clear();
+   newLinesBuffer_.reserve(newLineList_.size() * kBufferLength);
+   newIntegerBuffer_.clear();
+   newIntegerBuffer_.reserve(newLineList_.size() * kVerticesPerRectangle *
+                             kIntegersPerVertex_);
+   newHoverLines_.clear();
+
+   for (auto& di : newLineList_)
+   {
+      BufferLine(di);
+   }
+}
+
+void GeoLines::Impl::BufferLine(
+   const std::shared_ptr<const GeoLineDrawItem>& di)
+{
+   // Threshold value
+   units::length::nautical_miles<double> threshold = di->threshold_;
+   GLint thresholdValue = static_cast<GLint>(std::round(threshold.value()));
+
+   // Start and end time
+   GLint startTime =
+      static_cast<GLint>(std::chrono::duration_cast<std::chrono::minutes>(
+                            di->startTime_.time_since_epoch())
+                            .count());
+   GLint endTime =
+      static_cast<GLint>(std::chrono::duration_cast<std::chrono::minutes>(
+                            di->endTime_.time_since_epoch())
+                            .count());
+
+   // Latitude and longitude coordinates in degrees
+   const float lat1 = di->latitude1_;
+   const float lon1 = di->longitude1_;
+   const float lat2 = di->latitude2_;
+   const float lon2 = di->longitude2_;
+
+   // TODO: Base X/Y offsets in pixels
+   // const float x1 = static_cast<float>(di->x1_);
+   // const float y1 = static_cast<float>(di->y1_);
+   // const float x2 = static_cast<float>(di->x2_);
+   // const float y2 = static_cast<float>(di->y2_);
+
+   // Angle
+   const units::angle::degrees<double> angle =
+      util::GeographicLib::GetAngle(lat1, lon1, lat2, lon2);
+   const float a = static_cast<float>(angle.value());
+
+   // Final X/Y offsets in pixels
+   const float hw = di->width_ * 0.5f;
+   const float lx = -hw;
+   const float rx = +hw;
+   const float ty = +hw;
+   const float by = -hw;
+
+   // Modulate color
+   const float mc0 = di->modulate_[0];
+   const float mc1 = di->modulate_[1];
+   const float mc2 = di->modulate_[2];
+   const float mc3 = di->modulate_[3];
+
+   // Update buffers
+   newLinesBuffer_.insert(newLinesBuffer_.end(),
+                          {
+                             // Line
+                             lat1, lon1, lx, by, mc0, mc1, mc2, mc3, a, // BL
+                             lat2, lon2, lx, ty, mc0, mc1, mc2, mc3, a, // TL
+                             lat1, lon1, rx, by, mc0, mc1, mc2, mc3, a, // BR
+                             lat1, lon1, rx, by, mc0, mc1, mc2, mc3, a, // BR
+                             lat2, lon2, rx, ty, mc0, mc1, mc2, mc3, a, // TR
+                             lat2, lon2, lx, ty, mc0, mc1, mc2, mc3, a  // TL
+                          });
+   newIntegerBuffer_.insert(newIntegerBuffer_.end(),
+                            {thresholdValue,
+                             startTime,
+                             endTime,
+                             thresholdValue,
+                             startTime,
+                             endTime,
+                             thresholdValue,
+                             startTime,
+                             endTime,
+                             thresholdValue,
+                             startTime,
+                             endTime,
+                             thresholdValue,
+                             startTime,
+                             endTime,
+                             thresholdValue,
+                             startTime,
+                             endTime});
+
+   if (!di->hoverText_.empty())
+   {
+      const units::angle::radians<double> radians = angle;
+
+      const auto sc1 = util::maplibre::LatLongToScreenCoordinate({lat1, lon1});
+      const auto sc2 = util::maplibre::LatLongToScreenCoordinate({lat2, lon2});
+
+      const float cosAngle = cosf(static_cast<float>(radians.value()));
+      const float sinAngle = sinf(static_cast<float>(radians.value()));
+
+      const glm::mat2 rotate {cosAngle, -sinAngle, sinAngle, cosAngle};
+
+      const glm::vec2 otl = rotate * glm::vec2 {-hw, +hw};
+      const glm::vec2 otr = rotate * glm::vec2 {+hw, +hw};
+      const glm::vec2 obl = rotate * glm::vec2 {-hw, -hw};
+      const glm::vec2 obr = rotate * glm::vec2 {+hw, -hw};
+
+      newHoverLines_.emplace_back(
+         LineHoverEntry {di, sc1, sc2, otl, otr, obl, obr});
+   }
+}
+
 void GeoLines::Impl::Update()
 {
+   // If the lines have been updated
    if (dirty_)
    {
       gl::OpenGLFunctions& gl = context_->gl();
 
-      texture_ =
-         util::TextureAtlas::Instance().GetTextureAttributes(kTextureName);
-
-      // Latitude and longitude coordinates in degrees
-      const float lx = points_[0].latitude_;
-      const float rx = points_[1].latitude_;
-      const float by = points_[0].longitude_;
-      const float ty = points_[1].longitude_;
-
-      // Offset x/y in pixels
-      const float ox = width_ * 0.5f * cosf(angle_);
-      const float oy = width_ * 0.5f * sinf(angle_);
-
-      // Texture coordinates
-      static constexpr float r = 0.0f;
-
-      const float ls = texture_.sLeft_;
-      const float rs = texture_.sRight_;
-      const float tt = texture_.tTop_;
-      const float bt = texture_.tBottom_;
-
-      float mc0 = 1.0f;
-      float mc1 = 1.0f;
-      float mc2 = 1.0f;
-      float mc3 = 1.0f;
-
-      if (modulateColor_.has_value())
-      {
-         boost::gil::rgba8_pixel_t& mc = modulateColor_.value();
-
-         mc0 = mc[0] / 255.0f;
-         mc1 = mc[1] / 255.0f;
-         mc2 = mc[2] / 255.0f;
-         mc3 = mc[3] / 255.0f;
-      }
-
-      const float buffer[kNumRectangles][kVerticesPerRectangle]
-                        [kPointsPerVertex] = //
-         {                                   //
-          // Line
-          {
-             {lx, by, -ox, -oy, ls, bt, r, mc0, mc1, mc2, mc3}, // BL
-             {lx, by, +ox, +oy, ls, tt, r, mc0, mc1, mc2, mc3}, // TL
-             {rx, ty, -ox, -oy, rs, bt, r, mc0, mc1, mc2, mc3}, // BR
-             {rx, ty, -ox, -oy, rs, bt, r, mc0, mc1, mc2, mc3}, // BR
-             {rx, ty, +ox, +oy, rs, tt, r, mc0, mc1, mc2, mc3}, // TR
-             {lx, by, +ox, +oy, ls, tt, r, mc0, mc1, mc2, mc3}  // TL
-          }};
-
+      // Buffer lines data
+      gl.glBindBuffer(GL_ARRAY_BUFFER, vbo_[0]);
       gl.glBufferData(GL_ARRAY_BUFFER,
-                      sizeof(float) * kBufferLength,
-                      buffer,
+                      sizeof(float) * currentLinesBuffer_.size(),
+                      currentLinesBuffer_.data(),
                       GL_DYNAMIC_DRAW);
 
-      dirty_ = false;
+      // Buffer threshold data
+      gl.glBindBuffer(GL_ARRAY_BUFFER, vbo_[1]);
+      gl.glBufferData(GL_ARRAY_BUFFER,
+                      sizeof(GLint) * currentIntegerBuffer_.size(),
+                      currentIntegerBuffer_.data(),
+                      GL_DYNAMIC_DRAW);
    }
+
+   dirty_ = false;
+}
+
+bool GeoLines::RunMousePicking(
+   const QMapLibreGL::CustomLayerRenderParameters& params,
+   const QPointF& /* mouseLocalPos */,
+   const QPointF&   mouseGlobalPos,
+   const glm::vec2& mouseCoords,
+   const common::Coordinate& /* mouseGeoCoords */,
+   std::shared_ptr<types::EventHandler>& /* eventHandler */)
+{
+   std::unique_lock lock {p->lineMutex_};
+
+   bool itemPicked = false;
+
+   // Calculate map scale, remove width and height from original calculation
+   glm::vec2 scale = util::maplibre::GetMapScale(params);
+   scale = 2.0f / glm::vec2 {scale.x * params.width, scale.y * params.height};
+
+   // Scale and rotate the identity matrix to create the map matrix
+   glm::mat4 mapMatrix {1.0f};
+   mapMatrix = glm::scale(mapMatrix, glm::vec3 {scale, 1.0f});
+   mapMatrix = glm::rotate(mapMatrix,
+                           glm::radians<float>(params.bearing),
+                           glm::vec3(0.0f, 0.0f, 1.0f));
+
+   units::length::meters<double> mapDistance =
+      (p->thresholded_) ? util::maplibre::GetMapDistance(params) :
+                          units::length::meters<double> {0.0};
+
+   // If no time has been selected, use the current time
+   std::chrono::system_clock::time_point selectedTime =
+      (p->selectedTime_ == std::chrono::system_clock::time_point {}) ?
+         std::chrono::system_clock::now() :
+         p->selectedTime_;
+
+   // For each pickable line
+   auto it = std::find_if(
+      std::execution::par_unseq,
+      p->currentHoverLines_.crbegin(),
+      p->currentHoverLines_.crend(),
+      [&mapDistance, &selectedTime, &mapMatrix, &mouseCoords](const auto& line)
+      {
+         if ((
+                // Placefile is thresholded
+                mapDistance > units::length::meters<double> {0.0} &&
+
+                // Placefile threshold is < 999 nmi
+                static_cast<int>(std::round(
+                   units::length::nautical_miles<double> {line.di_->threshold_}
+                      .value())) < 999 &&
+
+                // Map distance is beyond the threshold
+                line.di_->threshold_ < mapDistance) ||
+
+             (
+                // Line has a start time
+                line.di_->startTime_ !=
+                   std::chrono::system_clock::time_point {} &&
+
+                // The time range has not yet started
+                (selectedTime < line.di_->startTime_ ||
+
+                 // The time range has ended
+                 line.di_->endTime_ <= selectedTime)))
+         {
+            // Line is not pickable
+            return false;
+         }
+
+         // Initialize vertices
+         glm::vec2 bl = line.p1_;
+         glm::vec2 br = bl;
+         glm::vec2 tl = line.p2_;
+         glm::vec2 tr = tl;
+
+         // Calculate offsets
+         // - Rotated offset is half the line width (pixels) in each direction
+         // - Multiply the offset by the scaled and rotated map matrix
+         const glm::vec2 otl = mapMatrix * glm::vec4 {line.otl_, 0.0f, 1.0f};
+         const glm::vec2 obl = mapMatrix * glm::vec4 {line.obl_, 0.0f, 1.0f};
+         const glm::vec2 obr = mapMatrix * glm::vec4 {line.obr_, 0.0f, 1.0f};
+         const glm::vec2 otr = mapMatrix * glm::vec4 {line.otr_, 0.0f, 1.0f};
+
+         // Offset vertices
+         tl += otl;
+         bl += obl;
+         br += obr;
+         tr += otr;
+
+         // TODO: X/Y offsets
+
+         // Test point against polygon bounds
+         return util::maplibre::IsPointInPolygon({tl, bl, br, tr}, mouseCoords);
+      });
+
+   if (it != p->currentHoverLines_.crend())
+   {
+      itemPicked = true;
+      util::tooltip::Show(it->di_->hoverText_, mouseGlobalPos);
+   }
+
+   return itemPicked;
 }
 
 } // namespace draw
diff --git a/scwx-qt/source/scwx/qt/gl/draw/geo_lines.hpp b/scwx-qt/source/scwx/qt/gl/draw/geo_lines.hpp
index 42b04447..e7564698 100644
--- a/scwx-qt/source/scwx/qt/gl/draw/geo_lines.hpp
+++ b/scwx-qt/source/scwx/qt/gl/draw/geo_lines.hpp
@@ -14,6 +14,8 @@ namespace gl
 namespace draw
 {
 
+struct GeoLineDrawItem;
+
 class GeoLines : public DrawItem
 {
 public:
@@ -26,48 +28,109 @@ public:
    GeoLines(GeoLines&&) noexcept;
    GeoLines& operator=(GeoLines&&) noexcept;
 
+   void set_selected_time(std::chrono::system_clock::time_point selectedTime);
+   void set_thresholded(bool thresholded);
+
    void Initialize() override;
    void Render(const QMapLibreGL::CustomLayerRenderParameters& params) override;
    void Deinitialize() override;
 
-   /**
-    * Sets the geographic coordinate endpoints associated with the line.
-    *
-    * @param latitude1 Latitude of the first endpoint in degrees
-    * @param longitude1 Longitude of the first endpoint in degrees
-    * @param latitude2 Latitude of the second endpoint in degrees
-    * @param longitude2 Longitude of the second endpoint in degrees
-    */
-   void SetPoints(float latitude1,
-                  float longitude1,
-                  float latitude2,
-                  float longitude2);
+   bool
+   RunMousePicking(const QMapLibreGL::CustomLayerRenderParameters& params,
+                   const QPointF&                        mouseLocalPos,
+                   const QPointF&                        mouseGlobalPos,
+                   const glm::vec2&                      mouseCoords,
+                   const common::Coordinate&             mouseGeoCoords,
+                   std::shared_ptr<types::EventHandler>& eventHandler) override;
 
    /**
-    * Sets the modulate color of the line. If specified, the texture color will
-    * be multiplied by the modulate color to produce the result.
+    * Sets the visibility of the geo lines.
     *
-    * @param color Modulate color (RGBA)
-    */
-   void SetModulateColor(boost::gil::rgba8_pixel_t color);
-
-   /**
-    * Sets the width of the line.
-    *
-    * @param width Width in pixels
-    */
-   void SetWidth(float width);
-
-   /**
-    * Sets the visibility of the line.
-    *
-    * @param visible
+    * @param [in] visible Line visibility
     */
    void SetVisible(bool visible);
 
+   /**
+    * Resets and prepares the draw item for adding a new set of lines.
+    */
+   void StartLines();
+
+   /**
+    * Adds a geo line to the internal draw list.
+    *
+    * @return Geo line draw item
+    */
+   std::shared_ptr<GeoLineDrawItem> AddLine();
+
+   /**
+    * Sets the location of a geo line.
+    *
+    * @param [in] di Geo line draw item
+    * @param [in] latitude1 The latitude of the first endpoint of the geo line
+    * in degrees.
+    * @param [in] longitude1 The longitude of the first endpoint of the geo line
+    * in degrees.
+    * @param [in] latitude2 The latitude of the second endpoint of the geo line
+    * in degrees.
+    * @param [in] longitude2 The longitude of the second endpoint of the geo
+    * line in degrees.
+    */
+   static void SetLineLocation(const std::shared_ptr<GeoLineDrawItem>& di,
+                               float latitude1,
+                               float longitude1,
+                               float latitude2,
+                               float longitude2);
+
+   /**
+    * Sets the modulate color of a geo line.
+    *
+    * @param [in] di Geo line draw item
+    * @param [in] modulate Modulate color
+    */
+   static void SetLineModulate(const std::shared_ptr<GeoLineDrawItem>& di,
+                               boost::gil::rgba8_pixel_t               color);
+
+   /**
+    * Sets the modulate color of a geo line.
+    *
+    * @param [in] di Geo line draw item
+    * @param [in] modulate Modulate color
+    */
+   static void SetLineModulate(const std::shared_ptr<GeoLineDrawItem>& di,
+                               boost::gil::rgba32f_pixel_t modulate);
+
+   /**
+    * Sets the width of the geo line.
+    *
+    * @param [in] width Width in pixels
+    */
+   static void SetLineWidth(const std::shared_ptr<GeoLineDrawItem>& di,
+                            float                                   width);
+
+   /**
+    * Sets the visibility of the geo line.
+    *
+    * @param [in] visible
+    */
+   static void SetLineVisible(const std::shared_ptr<GeoLineDrawItem>& di,
+                              bool                                    visible);
+
+   /**
+    * Sets the hover text of a geo line.
+    *
+    * @param [in] di Geo line draw item
+    * @param [in] text Hover text
+    */
+   static void SetLineHoverText(const std::shared_ptr<GeoLineDrawItem>& di,
+                                const std::string&                      text);
+
+   /**
+    * Finalizes the draw item after adding new lines.
+    */
+   void FinishLines();
+
 private:
    class Impl;
-
    std::unique_ptr<Impl> p;
 };