I also use a Polar watch and often wear it when I swim. The chest strap is no bother in the water, in fact, I often wear a jog bra under my suit too so that I can get out of the water, throw on my shoes, and start my run right from the pool. When the water is cold the bra helps to keep me warmer!

The strap is adjustable and fits me as well as my husband and he outweights me by at least 50 pounds.

The cardio equipment at my exercise club does pick up my heart rate from my strap and displays it for me on the machine. I like the fact that I can so easily keep my eye on the number without any worry of sweaty hands or wear I grasp the handle. It keeps me motivated and makes it easy to vary the intensity of my workouts...helps to keep me from getting bored.

I also use the Polar watch made for biking and I leave that one mounted on the handlebars and only remove it to change batteries. However, I must admit that I'm an information junkie and at Christmas my husband bought me a garmin for my bike too. That one shows more information, but I've been having some trouble with the unit holding a battery charge and I find that I still depend on my trusty Polar.

I would recommend that you try to stick with the same system both for running and biking as the strap from my polar will not work with the garmin and who wants to wear two straps, especially when racing.