Hello @clarak very cool project, I’ve been prototyping and testing a similar type of project for still images, source code here: GitHub - nickraymond/bm_rpi_camera_module: Underwater raspberry pi camera with Bristlemouth · GitHub.
You can find a few examples on how to beak down the image into smaller messages and then stitch the messages back together to display in a UI in the repo.
Energy will be a big factor, if you want to live stream I suspect you will want bigger batteries and more solar panels. I’ve been using the sixfab 4g/LTE hat with the pi zero and have been getting 1.3 Mb/sec upload rates with this sim card. I’m currently testing a 30W panel with 100Wh battery and getting good results.
Getting a video stream would be really cool! I’ve been able to get images through the Sofar API usin HEIC compression. Details here.
Hope that helps.