The kit exchange. I had heard of people panicking during the kit exchange and didn't understand why, especially as at DM level they should be fairly experienced. Until I tried it myself and realised that it is harder than it sounds.

Basically, you have to exchange every item of kit apart from your wetsuit with your buddy. Underwater, naturally. Now, I knew the mask exchange wasn't going to be easy because I'm short-sighted and have to keep my eyes screwed closed so my contact lenses didn't float away. In retrospect, leaving them out for the duration might have been a brighter idea but hindsight is never myopic. Anyway, here are Auntie Coldhand's tips:

• Start off in each other's kit. That way, when you exchange you are putting on your own stuff which  fits and with which you are more familiar.
• Agree with your buddy who is going to remove their kit first.You'd think you'd be able to do it all at the same time but trust me on this. One of you removes their first item and you watch them while they do this. When it is removed, they watch you while you remove yours. Then you watch as they put on your kit and vice versa. It sounds a slow way of doing something you probably want to get over as soon as possible but the key here is control, not speed. Just take it step by step.
• Start with the diving mask. It is the worst part for most people and you will be more comfortable when your own mask is securely fitted again, allowing you to concentrate better on the rest of the exchange.
• Practise removing your BCD to your right side so you can keep the regulator in your mouth; try to take it off towards the left and you will throttle yourself with your hoses and your reg will pop out.
• Hold onto each other, even if it is just by the elbow. It's comforting to know that your buddy is right there looking after you, especially if you have your arm caught up in your gauges and you've just knocked your mask off.
• If you have very much bigger or smaller feet than your buddy, make sure they know how to adjust your fins before you get underwater. If you are the one with the little feet, adjust them to the biggest size before you hand them to your buddy so all they have to do is tighten them.

I hope that helps someone out there. I  haven't had a panic moment yet in diving but the kit exchange was the closest I've come and I definately wanted to be at the surface but just knowing that my buddy was there beside me and looking after me kept me calm.