There are plenty of great programmes here about WW1 and some about the battle of Jutland and the German High Seas fleet, with the recent discovery of a survivor in Portsmouth harbour of all places.
I wonder if Dan and his team would consider making a programme about the salvage of some of the German High Seas fleet from Scapa Flow in the '20s & 30's? It seems to be a forgotten saga!
Ernest Cox bought the fleet and then spent some 20 years salvaging a lot of it. Gerald Bowman's book "The man who bought a navy" is a fascinating insight. I have come across odd snippets of film of this epic salvage operation, but I'm sure that Dan & his team would be able to unearth more of this extraordinary story.