Comparison - Garmin Vivoactive vs Fitbit Surge...

Hello ladies & gents!
I'm a very happy Fitbit Flex wearer/user. However, I'm thinking of upgrading to the Surge, but ideally I'd like to be able to swim laps without taking it off (no point having a hr monitor if I can't use it for one of my main exercises!)...

I've been comparing the Garmin Vivoactive and the Fitbit Surge and I'm a bit confused - they are both rated to 5ATM which should mean that they are lap swimming OK - but the Fitbit Surge webpage says that it's not suitable for swimming whereas the Garmin Vivoactive webpage says that it is suitable for swimming and it's also got the swimming app.

Colour me confused...

Now, I do have a Polar FT60 hr monitor and the strap doesn't annoy me (that's not why I want to upgrade), but if I could combine the FT60 and the Flex, I'd be a happy girl! I'm mostly frustrated by the fact that I have to switch the Flex to my other wrist when I'm working out because the Flex presses the pause button on the FT60 and so, if I don't notice it, I miss tracking part of my workout.

Has anyone got either the Surge or the Vivoactive and regularly swims laps (or just casually mucking around) with them on?

What are the other pros/cons that you've noticed?