... I have a question though: What does "two
group 27 Trojan batteries" mean? How many batteries
are we talking about here? How many in a group?

Two as in the number of batteries in series necessary to supply 24 volts to
my 24 volt trolling motor. Group 27 is the size. Group 31 would be larger.
Group 24 would smaller.

This means you have 4 batteries, and two in each group. This sounds
like more batteries than I have expected. May be I can make do with a
12-volt motor with 2 batteries (of course with a small rowboat, not a
20-ft boat).

Thanks for the info.

Depends on the river. I run a 20' bass boat on the river here. I see no
reason a row boat couldn't be used on a river along with an appropriate
outboard. Now if you are talking lots of long shallow areas with lots of
rocks to dodge around a canoe would be better and a rubber boat might be
better yet.

No, I am not likely to use a rowboat in the section of river that I
have in mind. That section of river is primarily for canoes. No
problem. I just have to rent one.

Jay Chan