Advice/suggestions on keeping me and my crew hydrated on a multhour sailing race

Some context, I'm part of a historic boat club here in the Cayman Islands. In October we have an annual long distance race across the north sound of the island where we sail our local sail craft the Cayman Cat Boat. These are shallow draft,double ended, open hull working style catboats with no external ballast, no dagger/center boards a lot of canvas and a keel that is measure in inches.

I've been sailing and working with these boats since I was a child but this year iv been asked to sail with and teach a new novice crew for the upcoming race. Both have sailing experience but not in these boats. I'm confident in their abilities to learn and even if we don't win I'm happy just to have new people out. Anyway enough rambling, one of the problems we have is that because these boats work their crews pretty hard and this race runs anywhere from 4 to 6 hours under the Caribbean sun, dehydration is always a concern. Problem is, it's not like I can say,just grab a Gatorade from the cooler or whatever, these boats are touchy and balancing the crew is super important to not end up swamped by a wave. For those of you who may take part in somthing similar, do you have any ideas? I was thinking perhaps camelbacks but I don't know if they would restrict movement or carry enough water.