My guess is that the rules for "carrying" a loaded handgun on a boat in
Maryland waters is the same as "carrying" anywhere else in the state:
you need a carry permit. On land, without a permit, you can transport an
unloaded handgun to a dealer's, from a dealer's, to a range, et cetera.


this past summer while scoping out some secret lobster holes 'out of
season', i was stopped and the crew checked all the usual safety stuff.
the dive flag i had up, we were just snorkeling, but still people in the
water, was not the appropriate size. i had the full sized one on hand,
just not up. i got a warning for that.

i had mentioned to the officer in charge when he asked for the
registration, flares, etc. "i have a handgun in that same bag" well
before i even made amove towards the boat bag. they didn't seem to
flinch or care, or maybe i was being watched more carefully and did not
notice. i do have a carry permit, so i have nothing to worry about
there, but afterwards is not the time to give them an 'i told you so'
defene.