Hi - I live in the North East US and have an Inspire 1 which we are using for marine mammal research off various boats. We also fly a custom built hex that has Mikrokopter software and we use their Boat Mode very successfully. It recalls the calibrations from when last ashore and does really well. I have had some good Inspire flights off one of the same boats (an aluminum sailboat), but twice now after 3 or 4 good flights on each occasion, I have turned things on and got no error messages, but then when ready to launch, (we do an auto takeoff hand launch), as you slide the ribbon to confirm, it gives an IMU error. A couple of times rebooting everything fixes it and it then flies fine, but then it wont fix with a reboot. Maybe I need to keep trying till it is happy? When I came back to land it turned on just fine and did not ask for an IMU recalibration. There was only 8 knots of wind and no appreciable sea state. My guess there is enough motion that the IMU cant lock on at sea at times, but is fine once on terra firma again, but would appreciate any thoughts. And no, I will never attempt to calibrate IMU or compass at sea. And yes I have the necessary permits to fly over marine mammals for research.