There were 116 German UBoats sunk after the end of WW2 in an operation called "Operation Deadlight". These subs are therefore known as 'deadlights', and are obviously far less interesting than an operational UBoat (sunk in action), of which there are very few.
They were sunk by various means and were all supposed to be in over 100 metres of water - however, half of them are found in less than this. This wreck lies in 92 metres of water.
The 9 day diving trip took place off Donegal, Ireland from the "Rosguill", skippered by Michael McVeigh.
The deep diving team was led by Barry McGill of Indepthtechnical.