Try to think of pudding. Granola Bars Moving away from medicine toward food, granola bars and the like have most of the user-friendliness of energy bars and more flavor. Unfortunately, most granola bars have more fat and less fuel than sports bars, but they're still a good choice. The price is lower too. Stay away from the chocolate flavors in favor of the oatmeal and fruit varieties.
Bagels are especially durable in the dive boat environment.
Rice cakes are probably the healthiest if you can overcome the suspicion that they're really styrofoam. Bread is almost the only thing good for you in a sandwich, since meat is mostly fat and protein, neither of which gives you short-term energy. Fruit Actual food in its natural state, like fruit, may be the best idea. Apples and oranges are also excellent, though a little acidic for some. Dried fruit is more compact and durable, but also more expensive.