Get it bundled.
It'll be loads cheaper.
If you want pool use there's a HR-swim belt. Does the logging thing, and has a wider sticky strap to still stable.
The HR-tri does both clever run metrics and swim logging
There's a bundle with both belts. Which would be best I guess.
Oooh, nice. Will look to get one when I get my 920XT (or equivalent) early next year...