I'm really pleased you got it sorted. Can you take the new one to the Lido for a practice before your race? A couple of goes in it will rebuild any lost confidence very quickly.
Absolutely, I plan to give it two or three test spins before the event. You really can't beat going into an event feeling like you're confident and haven't got to worry about it. We live and learn, whatever doesn't kill us makes us stronger and all that!
Thanks all for your words, kind and unkind! Daylight don't worry about being patronising, (you weren't) but I'd take being patronised but learning something useful because of it.
Last night I went to visit a friend, a damn good triathlete by anyone's standards and I expect to see him line up in kona next year. He was absolutely flabbergasted at my wetsuit, not only is it poor quality, but he said it was at least two sizes too big. I said to him as I've said in my OP, I've never seen another wetsuit so I wouldn't know the difference between large and small. He then put on his own suit and showed me the difference and it was stark. He's genuinely shocked I managed to get around 750m as he's certain I was probably carrying quite a few kilograms of water in my suit.
I feel 100% more confident now, I have a new wetsuit that I've tried on and actually fits and I've been given a pretty comprehensive lesson in putting it on and pulling up the material to the shoulders and crotch. Looking forward to testing it out now, but it does seem like the majority of responses on here were spot on, it was the wetsuit and not a pacing or weak mentality which thankfully can be fixed much quicker. Can't thank everyone enough for their help on here, some suggestions if never have though of and hopefully the thread can help other newbies in future who suffer from this issue too.
You may need a new suit. Do you have any tri shops nearby you can try ones on at?
I live in Central London, my local Runners Need/Cycle Surgery has a triathlon section but not sure they know their swimming like they know their bikes. So if anyone can recommend any wetsuit specialists in the smoke, I'll happily check them out.
So I got back on the horse yesterday evening, took the wetsuit to a local lido and I made a conscious effort to pull the suit up as much as possible around the legs and shoulders. Had a trisuit underneath to keep as many variables the same as possible.
It was better than the DNF swim, but still not even close to being as effortless as non-wetsuit swim. I can still get into the wetsuit in a matter of minutes and can get out of it within 60 seconds or so. I suspect as many of you have suggested that it's just a bad wetsuit fit or it's not been worn in (I assume this is needed with a wetsuit). Within 400m, my shoulders are getting heavy again and when I get out of the water I practice my stroke without water resistance and its definitely more difficult, almost as if I have a very light resistance band pulling my arm back when trying to move it forward which must all accumulate after quite a few strokes in the water.
Seems I've got to wear this suit to death before the 70.3 to break it in, or get a new suit and try and break that in. Either way, I'll be pacing the 1900m extremely conservatively and have cast aside any plans for a great split time.
Thanks guys, I hope you're right! I'm meeting a friend on Friday who is an experienced triathlete, has broken an hour for an Ironman swim numerous times and he's going to give his two cents on if the wetsuit is worth keeping (and it's just a case of pulling it up more) or getting a smaller one is the only way.
That aside, all I can do is get swimming more in open water in the next few weeks and try and keep as relaxed and in my own race as much as possible on race day. Fingers crossed I can ignore the other competitors until I reach the swim exit and try and make up for it on the bike and run.