HMS Colossus - a memorable dive

During the summer of 2001, a group of divers from North Dorset Sub-Aqua Club became some of the first people to set eyes on the Colossus stern wreckage. Below, Robin of NDSAC recounts how it made for a memorable experience.

Members of NDSAC on holiday in Scilly


It was 5th June 2001.  We were on our third trip to the Scillies, diving with local skipper Jim Heslin who was well known in diving circles for the salvaging of HMS Association, the first treasure ship found in English waters.

We were discussing with Jim what to dive that day and he, knowing we enjoyed diving historic wrecks, said that Mac Mace, a local skipper and diver, had seen something at the end of a dive that looked interesting & old, but could not now relocate it. Mac had asked Jim if his visiting divers would like to have a look for it.  This was near what was known as the Colossus site, & we were all interested in doing a search for this object, whatever it might be.

Mac Mace had put in a shot in the vicinity.  I went in with Dave Gilby and we commenced a circular search.  By the time Dave had used half a bottle of air we had found nothing, so to save air and extend the dive I decided to abandon the systematic search and just drift.  Although this was enjoyable we still found nothing, and when Dave ran low on air I decided to carry on by myself while he returned to the boat. (We were at 12m, by the way.)  Dave ascended the SMB line & I waited until the boat arrived to pick him up, and then carried on with my dive. 

I turned right for a few minutes, and then right again to head back up-current towards the start point.  After a short time I found a thin brass concave disc about 3” in diameter.  A few seconds later I came across pieces of what looked like old timber, & then suddenly I was confronted by a bed of brass nails about a foot long, and rows of brass bars protruding from the seabed, about an inch and a half in diameter.  These were worn away about 6” from the bottom, and a number of them had broken off leaving pointed tusk-like protrusions.  Then as I looked around I saw a vast expanse of timber – I could only describe it as looking like the floor of a village hall!  I remember exclaiming to myself “Bloody hell, Jim, you didn’t tell us this was down here!”  Then it started to occur to me that this may not have been found before! (I didn’t connect it to what Mac was looking for.)  I had a quick look round & found a row of what looked like huge round bollards protruding from the sea floor – they were much larger than I could reach around.  I did not realise that these were in fact cannon still in place in their gun-ports!

By this time I was down to 20 bar, so I had to surface.  First I tied my SMB line to a bundle of the brass pins to mark the site but still leave the line retrievable, & surfaced holding the reel.  On the surface I saw another SMB a few yards away – so others had found the site as well: this turned out to be Gwyn & Giles.  Jim’s & Mac’s boats were alongside each other a few hundred yards away. 

So there it is, the dive I shall always remember!


HMS Colossus

A memorable dive
Debris field survey
Site stabilisation
Dive trail
Site plan