This was a key warmup for IMDE, being about 6 weeks ahead of IMDE. It was a key bit of my build phase. As a result I did not know how to approach this re intensity.
ie did I race this as a 1/2 IM? or use it as a IM race simulation, keeping my HR down at the levels required for that.

Well I fell in the middle.

Swim was OK, being against current for 2 of the 4 sections.

Bike - I could not get my HR down to my expected HR. I was intending to do 129, but it stayed at 140+ However, effort seemed easy so I did not worry about it too much. As a result had a solid bike without killing myself.

Run - kept to a 10min - 1 min run walk protocol. Its what I am gonna do in the race so lets do that here as well. HR was always up in the 150 zone, but I was feeling strong and was running past everyone. Only one other guy, (pirate TR) ran past me the whole run.

total time 5:05 - really happy and probably could have dipped below 5 hrs if I ran the whole way....

Learning points

For the IM, I MUST KEEP MY HR DOWN!!! don't forget there's a marathon at the end.

For the 1/2 IM I had lots left in the run tank, ie could save 10 mins by just running..?? or could go a little harder on the bike.