Thats 61 miles to the Gulf, easy distance to cover with higher power radio. Since you can't control the signal direction (unless you get a special antenna), you and the group communications can easily get mixed with marine radio. So besides being illegal, you could put someone in danger, radio waves propagate at the speed of light.
Reach out to a local HAM club, I bet they would love to have more potential operators and you can find someone to teach your group the class to pass the exam. One of the biggest advantages of HAM is you get to pick frequencies, marine radio is restricted to the pre-programmed bands. Then with HAM you can go direct between trucks, and if you get far from each other you can probably connect to a local repeater that will double or more your reach. The repeater is just that, a big ass antenna that takes your communications and rebroadcasts. Some repeaters also have phone capability, meaning you could ask the repeater to dial a number (phone patch) and make a call for you. And finally with APRS, most digital radios will track your location by repeaters (if you want) so others can see on-line where you are and your route. Looks like you have a really well sorted out rig, why not go with the best alternative for communication?
