Sailing lessons were avaiable, and David really wanted to have a go. I did a week's course in the Isle of Wight, learning to sail, many, many years ago, in fact I even qualified with a Royal Yachting Association's Certificate.
However, this was David's big moment. We paid extra for me to be a passenger while he learned. We expected the instructor to stay on the boat with us, but after a few simple directions, he let us out on our own.
We sailed off towards Ragent's own private island, did a few nice little turn, and then David delivered his new-found speciality: underwater sailing! Somehow he manage to steer the catemaran downwards, water started to cover the top, we were getting deeper and deeper into the sea.
Of course, the bouyancy of the boat means that it did "pop" up to the surface again after a little while, but it was an interesting experience!