When planning a charter vacation, it always seems like an additional opportunity to get some new gear! As in life, some of this "gear" is essential while other gear is simply nice to have.
A basic, and essential piece of gear, is a dry bag
. What is a dry bag, you ask? These handy dufflebags are evolved from the kayaking industry where you want to keep important things (like clothes, electronics, etc.) dry during long kayaking trips. The bags themselves are nylon coated with plastic to ensure the water cannot penetrate the fabric. Further, the opening of a dry back is easy to seal, roll up, and lock in place so that water cannot leak into the bag as it can with a zipper.
There are a variety of options. For instance, clear dry bags
make it easier to see what you're looking for when in a hurry to grab things like a camera. (see pic below)

Some bags even have backpack straps
.
Dry bags come in handy when heading out for a day day of exploring in the dinghy. They also help keep valuables - cameras, GPS units, etc. - safe and dry. We've used one many times when heading out for a snorkeling trip to places like the Tobago Cays. I've also used the same bag when fly-fishing. They roll up and pack very easily and help keep your valuables safe while in a wet and even sandy environment.
Put simply, this is the best $15 you'll spend as the applications for these cool bags are unlimited.