I agree - the wetsuit may be restricting or may pinch behind the knees, so maybe try one of the shorter swims first and see how you get on.

Well excuse me, some of us were just born breaststrokers and thats it. I used to do all the harbour swims breaststroke, including Rangitoto, until my freestyle improved. You will have the benefit of looking at the wonderful scenery, as well as keeping a straight line, so as long as your speed is OK you'll be fine. I would suggest not wearing a wetsuit for breaststroke tho as it may restrict your leg kick. Try the 1.6km Round North Head swim the week before the harbour crossing ( www.devoswim.org.nz )

I should imagine virtually everyone will be doing frontcrawl as its the faster stroke and easier to manoeuvre through the waves/currents. I usually do it all in frontcrawl with maybe the odd stroke or two of breaststoke if i need to catch my breath or get my bearings. I think you might struggle doing it all in breaststroke - can you honestly do nearly 3km solely of breaststroke without your legs cramping? I know i couldn't, even in a pool, and i train regularly. But ya know there's no rule to say you can't do it, so just do what you gotta do!