Positioning for a deep water start...

One thing to ask yourself though, are you a constant pace swimmer, or are you going to go out at a faster pace then settle in to what will get you a 30 minute swim?

If you're planning on going out fast then settling in, have you been training that way?  Can you swim 500 yards at 1:15-1:20/hundred, then settle in just under 1:30/hundred for another 1500 yards?

The reason I ask is that I have problems figuring out where to start myself, because I am at a level of fitness with my swimming now where I'm shooting for 30 minutes or less on a HIM, except I'll do it by swimming every hundred at the same pace.  So if I start at the front with the other 30 minute swimmers, I might get bumped around as they go out faster, then I'll catch up.  Or I can start 3-4 rows back, not risk the carnage, but have to weave around other swimmers the whole time.

Damn straight.

Unless you are nervous of contact or dreadfully slow and know you will be in peoples way.

I'm decently fast, top 25% maybe.  But I will get up front and know that I may be bumped a little at first before the faster swimmers are ahead of me.  I would rather have people try to get around me than try to keep passing people.

It also doesn't hurt that I'm a big guy, and strong swimmer, so contact is not an issue and doesn't even bother me.

Done!

I'm up front... Never swum with people around me but I'm a former rugby player so used to collisions!