IM with a Garmin?

If you have access to 2 Garmins that's probably the way to go.  I used my 305 on an early season  200km ride Saturday and it gave me a low battery warning after about 8 hours.  I charged it while I was riding, using a USB battery pack in my bento box.  But I don't think it would have made it the full 10 hours that Garmin advertises. 

I'm doing Ironman Canada in August.  I'm probably going to use my Forerunner 201 on the swim (remove the strap and put it in a zip-lock under the swim cap), then my 301 on the bike, and my 305 on the run.  I'd say the GPS data uploaded onto Motionbased is more important to me than the finisher t-shirt. 

Good question. 

I plan to do the same ... given the information available with the bike computer, I only need to know my HR number - so I'll use the low end Polar I have.

I do, however, want the GPS functionality of the Garmin during the run.  I have become addicted to the pace/hr information. 

I plan on doing this as well.

Thanks all for the input.

It sounds like the 2 Garmin approach is my best bet. It makes more sense to me than buying a low end HRM just for the bike. I already have 2 305's, only logical that I use them both (with the wife's permission to use hers, of course). I may take a minor time hit when I turn them on in transition, but I can get my stuff on while they sync up. I'm just aiming to finish the race.

I don't even plan on wearing a watch on the swim. All that would do is have me calculate finishing times in my head, and that's a trap I don't want to get into with my first IM.

Is there a way to do that after they've already been coded to different ones? I don't mind taking the time to change straps, but if I can save a minute...

I'm hoping that won't come into play.

It's actually so fast you could do it as you head out of T2, but it is better to have them set up before hand.  You just go through the menu to accessories and have it scan for the HRM.  It will find it in a few seconds.  It's a piece of cake.

The data recording mode doesn't affect battery life.  It just affects how long it takes to use up the trackpoint memory.  You can set the data recording to record data points  "Every Second" or "Smart Recording".  The limit is 3.5 hours of data at 1 point per second.  In Smart Recording mode you should be able to capture a 15-17 hour Ironman if you can keep the battery charged.

I strapped the cradle in between the watch and my polar bike mount before the ride. So the watch strap basically held it all together.   And I put some tape over the Mini-USB hole in the cradle in case of rain. 

I don't know what it's called.  Its silver.  I got it about 2 years ago.