Yes, we have many people using the system that way. You would set up each member with an equal percentage of use - the exact number would be something like 14.79% - most people err on the side of giving too much time per user because they almost never use all their time - so I'd use a percentage more like 15% or 16% per user.
This would give each user/member the 54 full days per year consistent with your contract with them.
Under the business site model, you can add as many boats as you wish - so you would just add any/all your fishing boats to the system.
You only have to add your members to the system once, but you will need to add them to each boat individually - we do it this way because most business have some different members on different boats.
Once you get your members added at the correct percentage, they will be able to reserve the boat using the automated system - they will get notifications, etc.
Let me know of any additional questions.
Kind regards,
John Davis