A few years ago I nearly got a TV job recreating the world's first ever working submarine, designed and made by Cornelius Drebble, and used on the Thames in the 17th century, and which even took King James underwater. It was rowed, the oars being sealed with double gaiters of leather filled with lanolin and fat, and Drebble even designed chemical re-breathing equipment. Sadly another programme was just ahead of ours and was about to start building, so the BBC refused to fund another. The recreation did work, but modern regulations and insurance limited what they were allowed to do with it. I was involved in recreating Halley's Diving Bell, which was filmed in an underwater filming tank used in lots of films and TV programmes. It was only about 6 metres deep, but the forces involved were astonishing: we needed 9 tons of stage weights to hold the beggar down, and one of the high tensile chains snapped, if you see the programme (What the Tudors and Stuarts Did For Us) you will notice that it is an an angle. Having been involved in that and seen how things behave, I now would be even less inclined to set foot in any submarine!
