I've used my Garmin 305 in 2 of my races, Olympic and Half-Iron, plus rode with it on multiple times in the rain w/ no damage - so, yes, it's waterproof.

I have done several triathlons with my garmin though I always just leave it on my bike during the swim. It has also been through several arizona rain storms with are really bad just fine. Can't say I'd recommend keeping it underwater for anytime though.

I found a waterproof box that the watch will fit in that is waterproof to 100 feet. The box is RF transparent so it will not interfere with GPS signal. I was going to create a strap so that I could attach the case to my lower back while I swam. However, my question is that the box is designed so that it will float, would I technically be allowed to use this during a race or would this be considered a floatation device. The case is not going to act like a life raft but it is designed to float with a cell phone or PDA in it so if you accidentally dropped it, it would not sink. I would more be interested in using it during training, but I might consider using it in a race if it was legal and non-constrictive.

I don't see why you would need to take the Forerunner with you during a race. You won't be able to check your HR while racing so you'll still have to stick with RPE. And you know the exact time and distance you swam anyway so you can figure out your pacing later. Basically I don't think its worth the hassle to try and make sure it would be legal in each race and then to remove it from the case and attach it to the bike.

It could be useful during training though, and then you don't need to worry about how much the case floats.

How do you use your Garmin 305 during races? Do you keep it on your bike while swimming and use it on the bike and run, sacrificing your total time on the watch not being accurate? Do you only use it as a bike computer?

Also, I have always just used it as a bike computer during a race because the wrist band used for running can cut your wetsuit when taking it off during transition if the garmin is not attached to it. Do you take the time to put the running wrist band on in transition? I basically want to know how you all use the garmin during a race.

It is funny how many Garmin users risk during the races. I have seen at least five people swim in Oly races with Garmin 205/305 on their wrist. I hope their units survived, but internet is full of stories of flooded Garmin units. I would not swim with one - and the water resistance was one reason for me to sell my Garmin 405 on eBay. I do not see a point to lose time in T1 with handling another piece of equipment when Polar or Suunto do the job quite nice and are approved for swimming (not diving - but that is entirely different discussion :-).

do you find it difficult to transfer the device to your wrist when you switch to the run? and do you where the wrsit band during the swim?

i have the rs200 without the foot pod
http://www.trifuel.com/product/10603/reviews

Just bought the 405 and wore it in an Oly a few weeks back (after a buddy told me he routinely wears his in the ocean and in training without incident). Mine hasn't worked perfectly since. Strange behaviors like going into and out of autopause (in my house) and the battery doesn't hold the charge it used to. I wish I could use this as a race device, because I find the pace information great on the run, and on the bike, it's nice to have a map drawn later (but I can deal without this). But my transitions are slow enough as it is, so for races in the future, I will wear my Suunto. For $300 you'd think Garmin would have made this watch waterproof to say 100 feet, as opposed to just water resistant. I like it so much as a training device, however, I won't part with it.