I think it all depends on the individual situation. How was everyone approached about the cost of the trip initially?

We've owned for over 4 years now, so it's been awhile since I organized a trip at regular rates, but when I did, I emailed everyone and gave a rough idea as to the costs - I think I approached it as being by cabin, but we ended up by person since we had 8 people one trip and 9 the other in a 4 cabin cat.

I think either way is fine as long as it's approached that way from the start.. Like I said, I started our trips by emailing all our friends and letting them know the per cabin cost. It only changed because we maxed out each cabin. I looked at it as us booking a hotel on the water. Like a hotel, everyone pays for their room. Then everything else (food, water..etc) is all per person.

No right or wrong answer though, so long as your entire group is ok with the way its done.

For costs during the trip, I keep a running spreadsheet that is broken out by family. When someone pays, they write their name on the receipt and put it in an envelope and every few days I update the spreadsheet to see where we stand - spreadsheet breaks it out as to what each family owes so we see who's behind, ahead and know who should pay for the next boat purchase. It's worked well for us, but just as in the boat cost, you need to make sure everyone is ok with splitting that way.