It would be great to add a note visible to other members of the boat share when creating a reservation. In many cases I'm not using the full slot time and I'd love to let the other members know - particularly for those booking adjacent to me.
For example if I book slot from 2-10 but don't plan to go out till about 4, I could add the note so the person with the slot from 8-2 could stay out a little longer. That's most of the reason why I'm messaging other people in the boat share.