Hello, I normally inhabit the forums over at ARRSE, but have a couple of questions someone here may be able to help me with. I'm doing a MSc in ocean and offshore technology at Cranfield University, and my research project is titled 'An investigation into corrosion on the Holland 5 submarine'. I've visited the Holland 1 in the museum at Gosport, and I've dived the Holland 5 (with the correct licence and documentation) to take thickness measurements of the hull. Despite my research I still haven't found definitive answers to the following questions: Which submarine was the first commissioned into service in the RN? Where would this information be located? Why did it sink whilst under tow in 1912? What fittings and fixtures were removed prior to its final sale? What would be peoples' general opinions on raising this wreck given that it will eventually corrode away? If anyone knows the answers to these questions, or has any more information on the Holland class in general or the Holland 5 in particular I'd be very grateful. Thank you.