Two friends of mine shared a boat. They're not friends anymore. One had to sell his house and move away. They lived next door to each other. Constant fighting on who got the boat each weekend, who did/didn't put gas in the boat. One didn't clean the boat to the others satisfaction, One forgot to add oil to the fuel and destroyed the motor, and was not able to pay for repairs or pay his "partner" for back for his investment. The guilty party felt that the best solution was to sell the boat "as-is" and split the money 50/50. The other partner felt that they should determine what the boat was worth if it was running and the guilty party should pay him that much money. That was a big difference in what the guilty party owed his "partner". The guilty party simply had no money to reimburse the neighbor. Not sure how complicated the contract would need to be to cover all possible problems. You might want to check into a "Freedom Boat Club" type ownership if there's one in your area.
