I work for Dakota Lithium, have had a few customers lose their batteries at the bottom of a lake or river. Best to have it in a waterproof battery box or dry bag tied down to the kayak as water damage isn't covered under warranty.
@@2ndnatureoutdoor140 most boxes you'll find are too small for a 100Ah battery, we just got our 100Ah down from group 31 to group 24 size by switching from cylindrical to prismatic cells.