Well tahoe 50 since you ask; and I am just an old country type feller. The least expensive and perhaps not the most environmentally friendly path I take as I am clearly in your shoes and not giving up on fishing. 5-gallon bucket double trash bag lined and if your worried about privacy, a long rain coat or poncho of some kind. Probably should not say this but I still have a burn barrel at home that takes care of the disposal issue.
Of course you can buy the portable apparatuses and buy all the biodegradable chemical and paper. Takes a lot of room up on the boat...... 5 gallon bucket and trash bags are multipurpose items.