Polar HRM and water resistance/swimming

Hi there! I have been using my Polar FT7 for about two months now with my gym workouts (spinning, elliptical, group fitness classes) and it has been a HUGE help in my weightloss & fitness goals. I am extremely happy with it.

My question is how safe is it to use in water? I am going on vacation soon and would like to use it while swimming laps in the pool but I am hesistant even though it claims to be water resistant. Any one have any problems or not?

Thanks for your feedback!