Tyler, what a great subject to bring up! As the skipper of a R-21ec with a female crew between the ages from 5yrs to 35yrs. This subject has come up numerous times! I carry a portable urinal (hospital type) for me and a female type for the girls, I also carry a 3 gallon bucket with a toilet seat, with disposal bags and a lid for the bucket that is water/ait tight. I do have the toilet and holding tank but find it useless when the younger crew member says it time and have to rearrange the cabin for them!
I have had friends and family fish with me and nature will call at the most inappropriate time! On my boat we take things in stride and enjoy! Lots of funny stories around the camp about Grandpa netting a big Salmon while holding the pole and sitting on the poop bucket.
Just enjoy and remember Poop-Happens! Bob