Oh boy,Christian - what can I say?
I only know Dray by reputation and also have not seen the book, so won't comment on it. But I'll make this observation. I am part of a team that used to organise underwater photography conferences in the UK. Speakers included Martin Edge, Mark Webster, Michael Aw, Paul Kay, Maria Munn, Peter Scoones, Colin Doeg and Peter Rowlands, all of whom have written books on how to take underwater photographs. Sitting in the audience alongside Peter Rowlands, I asked if he learnt anything from these festivals. Regarding me as one regards a fool, he said that of course he did. I believe each of those authors and the wonderful underwater photographers who we had who had produced books of underwater photographs (including Helmut Debelius, Paul Naylor, Alex Mustard, Tom Peschak, Don Tipton, Dos Winkel, Constantinos Petrinos, the Ferrarris, John Collins, David Doubilet to name a few for point scoring) would all agree with Peter. You become a better underwater photographer through seeing others work. The cost of taking underwater pictures is very high and the cost of obtaining one scrap of knowledge from a book very cheap - I'd be absolutely amazed if I could not glean something from Dray's book myself that I don't know He's a good photographer. I've been diving since I was sixteen and I'm now nearly fifty and been taking pictures for 20 years. With a little more experience and help from other people I hope to get good at both.
Dray, I wish you every success with the new book (I worked a little on Martin's by the way) and, Christian, I think you should buy a copy, read it objectively and then come back with an informed viewpoint.