They also come in wireless or non-wireless (ie., wire between the watch and the chest strap). The ones with a wire are supposed to be more accurate. The wireless ones are kind of handy, though, because the chest strap signal can be picked up not only by your watch but also by gym equipment, an HRM on a cyclometer, etc. (Of course, if other people around you are wearing wireless monitors, you can end up picking up each other's signals.--)

The chest strap is an elastic band that you can feed back and forth for a single or double thickness/length, so you won't have any trouble with fit.

Mine is said to be waterproof and can be worn swimming, but I can't say for sure because I've never tried it in the water.

Most of the models that measure distance have a fairly bulky display, as far as I know. I've heard a lot of mixed reviews about the Garmins. From what I've heard, the distance function works pretty well in the country but not as well in the city where there is more interference.--

Deb