Help! Looking for recipes to bring on boating weekend. So sick hamburgers and and hot dogs

If your captain & crew have similar tastes and you want ease of serving, some lovely over-packed sandwiches like eggplant parmigiana or pan bagnat.
If people have different tastes, maybe some sort of spread where they can pick from elements and assemble their own, like the Iraqi-Israeli sabich (roasted eggplant with hummus hard cooked egg amba etc) or a mezze meal with good breads and crackers.

To tag along off Dona's idea, you could marinate a flank steak beforehand and grill it. Also, grilled veggies would go great with a pesto sauce that you could make ahead. As for flank steak, I have made Jenny Rosenstrach's Tony's Steak recipe for years. Everyone loves it and you probably already have most of the marinade ingredients in your pantry.

Last outing we cooked fajitas at home and heated on the boat. We used a George Foreman grill to heat the tortillas.
Quesadillas work too.

One idea for an entree is beef satay, which is marinated ahead of time, then grilled a short time (2-3 minutes per side). Here is one recipe: https://www.foodnetwork.com/recipes/sandra-lee/beef-satay-recipe-2041449. When I make beef satay, I usually put my slices of beef onto two skewers (helps in turning them), and I also put some aluminum foil under the top and bottom parts of the skewers when they are on the grill, so they don't burn.

As for sides, perhaps a vinaigrette-based (no mayo) pasta salad. Here are a couple of possibilities: https://food52.com/recipes/23175-lemon-dill-orzo-pasta-salad-with-cucumbers-olives-feta
https://food52.com/recipes/23511-mediterranean-orzo-salad