diff --git a/buoy_interfaces/CMakeLists.txt b/buoy_interfaces/CMakeLists.txt
index 836d760..efa0be2 100644
--- a/buoy_interfaces/CMakeLists.txt
+++ b/buoy_interfaces/CMakeLists.txt
@@ -14,17 +14,20 @@ find_package(std_msgs REQUIRED)
 
 rosidl_generate_interfaces(${PROJECT_NAME}
   "msg/BCRecord.msg"
+  "msg/IncWaveHeight.msg"
+  "msg/LatentData.msg"
   "msg/PBCommandResponse.msg"
   "msg/PBRecord.msg"
+  "msg/PBWatch.msg"
   "msg/PCRecord.msg"
   "msg/SCRecord.msg"
   "msg/TFRecord.msg"
   "msg/XBRecord.msg"
-  "msg/PBWatch.msg"
   "srv/BCResetCommand.srv"
   "srv/BenderCommand.srv"
   "srv/BusCommand.srv"
   "srv/GainCommand.srv"
+  "srv/IncWaveHeight.srv"
   "srv/PCBattSwitchCommand.srv"
   "srv/PCBiasCurrCommand.srv"
   "srv/PCChargeCurrLimCommand.srv"
diff --git a/buoy_interfaces/msg/IncWaveHeight.msg b/buoy_interfaces/msg/IncWaveHeight.msg
new file mode 100644
index 0000000..2992abc
--- /dev/null
+++ b/buoy_interfaces/msg/IncWaveHeight.msg
@@ -0,0 +1,15 @@
+# relative_time is the time height was computed in decimal seconds
+# relative to simulation time in pose header.stamp
+# time of wave height = header.stamp + relative_time
+# Note: absolute_time from IncWaveHeight.srv converted to relative for response
+# Note: all fixed-points in SDF are computed with relative_time = 0.0
+float64 relative_time
+
+# For now, position is always in world coords (use_buoy_origin always False)
+bool use_buoy_origin
+
+# header.stamp = simulation time of computation
+#   time of wave height = header.stamp + relative_time
+# position = x, y, z(height above waterplane)
+# orientation = normal vector (slope of wave) at position
+geometry_msgs/PoseStamped pose
diff --git a/buoy_interfaces/msg/LatentData.msg b/buoy_interfaces/msg/LatentData.msg
new file mode 100644
index 0000000..0512f65
--- /dev/null
+++ b/buoy_interfaces/msg/LatentData.msg
@@ -0,0 +1,5 @@
+std_msgs/Header header
+
+IncWaveHeight[] inc_wave_heights
+
+# TODO(andermi) fill in other stuff
diff --git a/buoy_interfaces/srv/IncWaveHeight.srv b/buoy_interfaces/srv/IncWaveHeight.srv
new file mode 100644
index 0000000..146ddd8
--- /dev/null
+++ b/buoy_interfaces/srv/IncWaveHeight.srv
@@ -0,0 +1,24 @@
+# IncWaveHeight Request
+
+# relative_time in decimal seconds to evaluate height at time relative to now (0)
+# (Note: may be in future for wave prediction)
+float64[] relative_time
+
+# absolute_time in epoch decimal seconds (from 01/01/1970 or sim start) to evaluate height
+# (Note: may be in future for wave prediction)
+float64[] absolute_time
+
+bool use_relative_time
+
+# x, y is relative to buoy origin; otherwise world origin
+bool use_buoy_origin
+
+# x, y to evaluate height above waterplane
+geometry_msgs/Point[] points
+
+---
+
+# IncWaveHeight Response
+
+IncWaveHeight[] heights
+bool valid