Dry side electronics

Depends on your definition of satisfactory and which electronics package you plan on using. For example I think this works great so far My tether spool - #18 by piercet but i may be biased.

That protects the fathom X and some other bits. you would presumably want a waterproof ruggedized laptop to go with it. If you buy the USBL electronics it has its own waterproof case.