I think you may probably know that UHF stuff works just fine 'over' water, does terrible 'through' water. Keeping that in mind, most of the 2.4 Ghz systems are great for any R/C stuff except for submarines.
It's very common that different manufacturers do things just a little differently from each other, offer different 'features', etc. Find the brand that offers the features you want and give it a try. I'm not going to get into the 'brand' debate, they're really not all that different as far as capabilities go (besides, if it ain't Kenwood, you got squat! Right??