I have 3 Concord marine deep cycle 8D AGM batteries in the motorhome. 158 lbs. each.
Take a look at Interstate. The SCS series is marine deep cycle, used for trolling motors. The BCI series is marine deep cycle/starting.
Do a search for trolling motor batteries. Almost every manufacturer makes them. Some are designated as marine, some are not.
Cabelas sells bateries that are labeled marine/RV. Not sure who they are made by, never checked.
Did you read my second post? Thought I explained the two types quite clearly. Deep cycle and deep cycle/staritng. Two different animals.