Just signed up with some friends for a 3.5km swim across a lake. Hoping this is the motivating push I need to get back on track with working out and lose the pounds I gained over the past year.

I'm training in a pool and finding it difficult to keep counting laps. Anyone swim and use some sort of distance-tracking device or watch? All I really care about is distance and time. Don't need anything fancy, just something that won't get in my way. A quick google search seems to indicate a waterproof watch is probably the way to go.

Anyone use one that they would recommend?