Try turning your back foot to 45 degrees from the nose so your back knee is pointing the way you want to go, instead of out to the side.

That should help you get the shoulders square on:

Unfortunately it's almost impossible to see anything from that ☹️

From what you describe, it's possible that you're still not getting the weight on the front foot during the bottom turn and when you extend, but that's just a guess.

Jeff Wallace Yes, shortening the stance and getting your shoulders facing the nose will help 👍

I think perhaps the problem is that it's too far back, because it's preventing you from being able to look back to the foam and, instead, you're racing down the line.

Also it seems to be making you bend your waist instead of compressing on the front foot.

Try drawing a line on the ground and stand with your feet together at 45 degrees to it.

Pivot your back foot on the heel until it's at 90 degrees to the front foot, then pivot it again on the big toe until they're parallel.

Stack on the front foot and compress and extend a couple of times and let your back foot move to where it's comfortable, that's about how long your basic stance should be.

Try doing some surf skating in a bowl and get used to pivoting on the front leg.

Here's a pic of John John Florence that I've posted a few times before.

Look at how his coffee cup hand is low and forward like it's a surfboard skimming the wave, putting him in a "sprinter" stance as he holds the rail through the bottom turn 👍

This is from Dakine which is a good brand.

Also it's a £400 suit that I got in a closing down sale for £120 🤑

I have a 4/3 which is OK for much of the year,

and I do have a Rashie with hood that I can put under it, however it's a few years old now and when the temperature gets down below about 10 degrees C (especially if it's windy) I really want something warmer 😕

Terry W Problem is, I just took a skiing holiday in the Alps.

I can get waves here, I can't get mountains...

I've seen suggestions about hair conditioner, but I'd be dubious about the effects it might have on the suit and the environment, hence why I'd prefer a properly designed product.