Re: do you carry an acoustic Guitar?
I think its just a bad idea as humidity would not only affect the neck/body but the electric components as well. They are just not built to withstand that environment. The general cruiser rule of "everything must have a dual purpose" may dictate leaving the electric ashore anyway. Even if they built an electric ax able to withstand the elements, most couldn't afford giving up the storage. If you must, I think your best bet is to fit a pickup in your existing acoustic and find a small portable PA with mic and instrument inputs. Both Peavey and Fender make models which are somewhat smaller and I am sure there are other brands even more portable (Roland, Samson, etc).
If I was actively gigging as my primary source of income, I would consider a larger (but still portable) PA...but the crowd I usually play to are sitting in my cockpit or around the fire.
1983 Morgan OI 416