Compass and position jumping around

Hello,
yes I wrote a Python program as the software supplied with the USBL was quite buggy. It is located here: USBL Python topic. I saw that Blueprint Subsea now have a new software (PinPoint), it looks of better quality than the previous one (NavPoint), so I’ll give it a try on the lake before continuing with this Python script.

I calibrated the sensors and went for a test dive yesterday, it seems to work well without and with the USBL. The compass was stable. The conditions were very poor for the USBL (lying on the bottom near the shore) and depth was only 1-2m but it somewhat worked (some random 50m jumps, no jumps to Africa).
My attempt at drawing a square on the map:

I’ll check the output of nmea-receiver.py during the next dive, thanks for the hint.

I guess for now the ROV is ok and I’ll have to improve the USBL side, thanks for your help !