With my old new to me beater, I went to the trouble of finding the drain
plug (picked up the appropriate Seloc manual first) . I found that I can fit
a pan in there and drain the oil that way. I am more comfortable knowing
that the oil ... and any crud left by the previous owner(s) ... was/is
draining from the bottom of the pan rather than from who knows where using a
pump. And ... by removing the seat and so on, I got a good look at the lower
part of the engine ... oil cooler, hoses and so on ... to verify all was
well. And if you trailer the boat or take it out of the water now and then,
there is a replacement for the drain plug comprising a fitting and hose that
lets you drain the oil through the hull drain plug.

I don't know if there is a plug on the oil pan or not.
I'd either have to remove my whole rear seat (possibly openning a huge
can of worms) or stand on my head in the engine compartment to find
out.