Woodsie,
The first thing you need to do is decide what 'kind' of boat you want, scale, fast, electric, gas, etc, etc. How do you do that? Look around at the different internet sites, hobby stores, where ever, and see what's available in a 'RTR' (ready to run) form, and ARR (almost ready to run). You might also look at a few of the 'kits'.
Then, take a good look at the lake/pond you think you'd like to use. How big is it, or maybe, how big'a boat would 'fit', you know? Then decide how much you ~think~ you'd be willing to spend on what you'd need to get into the kind of boat you'd like to run. (Hint: Double your first estimate! LOL).
What happens when the batteries go dead? You have a choice, recharge them or replace them. Most people recharge them (add battery charger to the list). If they happen to go dead in the middle of the lake, you have two choices. Go swimming, or wait till it drifts to shore (only have to get wet to your knees then). Or the third choice, pay close attention to the boat's responses, when it gets 'sluggish', bring it to shore, NOW! (Having two or more battery packs means you can 'play' while the others are recharging. Ah, remember to run the car's motor so it doesn't go dead too! Real bummer.)
Most of the 'problems' with the model boating hobby are a 'problem' because people don't think far enough ahead. So, think first (and do what I say, not what I do, you know?). It's fun, even the 'probelms'...
- 'Doc