Advice for my first mass (full IM) swim start

Can you give us more info?  Which race?  What's your comfort level in the water?  What's your expected finish time? 

Depending on the race, I wouldn't automatically expect a fight at the beginning.  I've done 2X at IMAZ swim start, and one of my reports says "I've had worse sprints"

I've only done one mass start with about 1500 people.  It was a wade start, about 100 feet from shore.  So really only about 30% of the people were at the start buoys treading water, another 30% were in knee deep water standing, and the rest were on shore waiting for the gun before they jumped in the water.

It wasn't that bad.  It was crowded, but not that much more crowded than the other races I've done that had waves of about 100 people each.  Seeding yourself properly at the start is the key.

Pretty comfortable in the OW. Done Alcatraz a few times, a few Olys and a HIM in addition to just swimming in the ocean.  Specifically IM Arizona in the canal.  Not sure what the expected finish time for the FIM swim will be but was 32min in the HIM swim. 

I'm primarily worried about how long it takes for swimmers to begin spreading out and how much jostling is done at the start.  I find the swim once we are spread out to be no problem, but I hate the bumping and kicking at the start and spend a lot of energy just trying to find space to swim in a straight line.  Thanks for your help.

I'd start far left, away from the wall, in the front as you'll probably be swimming a low 1:XX, maybe even a high :5X.  At any rate, you are going to be near the pointy end, you should take advantage of that fact.  The wall side is much more crowded but it is more of a straight shot given the curve of TTL.  I've started wall and started buoy side, buoy was easier.

It will be a little bumpy at the beginning, but at your speed it should open up faily nicely within the first 500 yards or so. 

BTW, none of the recent events involved a mass IM start.  NY and KY were time trials.

No worries    Just found this pic in my facebook albums, I think it's from '08, but I'd imagine each year is similar, you can see the swimmer distribution

You mean you didn't order your wetsuit with the 6 inch spikes?

Seriously, though, anyone got pix from IMTX?

No, but Google IM WI swim start and check out the photos.  A few BTers have some of their own in the blogs, I believe, too.  I've experienced that mass start twice from the back, and it's still UNREAL!!

http://www.google.com/search?hl=en&q=ironman%20wisconsin%20swim%20start%20photos&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&tab=wi

well then... another opportunity to post this triathlon swim start training video:

http://www.youtube.com/watch?v=U_6tOzt-nfM

basically, it's going to be the same as your divided starts in terms of contact, but it will take much longer to "thin out" so you can expect to be close to somebody much of the race.

It never seemed much different to me starting with 20 people or a thousand, you are going to have some contact, be ok with it and move on.

Thanks for this.  This is exactly my worry, but looks like from your posts and the other helpful posts, that I just have to find relatively thinned out spot near the front and just tough it out for 10-15 minutes.

Awesome.  LOL.