Minimum for you to leave the dock

[grouchyturtle]

What kind of fine print do you have on your website and/or any other marketing materials to let the unreasonable types know that you need a minimum number of passengers to go out and/or they can opt to pay a surcharge for a pseudo private trip?

 

[Tortuga James]

My maximum for "unreasonable types" is zero.

In all seriousness, there is no magic in the answer to your question. Just say: "The boat cannot run a trip until X seats are sold".