It depends on what you mean by make money. Covering replacement and maintenance costs by charging more than fuel costs only is perfectly legitimate as long as it can reasonably be proved that the amounts charged are within reason.
This is for club members only, others cannot be charged extra money or it is a charter for profit.
No-one should be making money other than covering expenses and the club should not operate the boat at a profit.
It does cost a lot in maintenance to run a boat and depending on the amount of use and type of boat £120 over and above direct expenses could be either excessive or not.