Mike Cross reports from Devon on the first of a pair of weekends with the Nautical Archaeology Society working on the Salcombe cannon protected wreck project.


It started on a Thursday in April when we were invited to visit Northampton BSAC clubhouse to meet with members from the South West Maritime Archaeology Group (SWMAG). A collaboration between MSDS Marine, SWMAG and the Nautical Archaeology Society (NAS) commissioned by Historic England was looking for new members to get involved with maritime archaeology and Protected Wreck sites. In particular the Salcombe Cannon Protected Wreck site watched over by SWMAG. A few Marlin SAC members were interested so three of us went along to learn more and report back. Despite a few members being interested, only Mike W and myself could secure the time needed to sign up for both fieldwork sessions. You can read more about the project overview here: https://msdsmarine.com/nextpwageneration/

The first fieldwork dates in June were approaching and we received our first bit of homework from the Nautical Archaeology Society. We needed to complete two online courses, “Maritime Archaeology” and “Underwater Archaeology“. They are both very good courses and form a great introduction into archaeology in general as well as just the underwater kind. Both take quite a few hours to complete so we didn’t have time to hang around. https://www.nauticalarchaeologysociety.org/elearning

Fast forward to the end of June and we are arriving at the campsite in Salcombe that will be our base for the next few days. Mike W has a huge inflatable tent and Alison from MSDS Marine has prepared a spread of BBQ food so we are hardly roughing it. We meet with the other volunteers and the SWMAG members over food before John from the NAS gives us a demo on recording an underwater site, this is a practical exercise to build on our online learning. We end the night chatting to SWMAG team about their diving on the site and everyone is excited to get out tomorrow to see it for themselves.

Day One

Day one of diving and we meet the boat, Falcon 2, in Salcombe. The van is unloaded and everyone stows their gear on the boat. The wind is blowing and we are warned there’s a chance we will only get one dive in as it looks to be getting worse rather than better. As we head out from the haven of Salcombe the swell starts to build and crossing the bar turns in to an exciting ride. Arriving at the site it is confirmed that there would only be one dive today and a time limit of 50 minutes but the weather for tomorrow is looking much more promising. Armed with our cameras and a map of the site we jump in to see the wreck site for the first time. Descending down a long shot we were pleased to see the visibility below hasn’t been affected by the waves above.

I am buddied with Mike W as I have dived with him before. We are the second group in and are pleased to follow the shot down to the first cannon. From here on I am in charge of the map and navigation so no pressure! Luckily the position of the cannon and anchor, along with the sonar scan of the sea bed, make it much easier to find our way around an unknown site. While Mike photographs some other “interesting looking artefacts” I decide to try out the GoPro I’d been loaned for the dive. This model only has a screen on the front to tell you that it is working so every one of my videos starts with a selfie of me checking it is working. I’m told this could help with identifying who has taken the videos after a dive but I don’t think it will catch on. I’ve been playing with photogrammetry previously and this seems like a great opportunity to get some practice. I do a quick scan around the cannon hoping to get some tips from Tom (MSDS Marine) on what I can do to improve on the future dives.

NB: As a side note here the photogrammetry of the cannon did come out rather well. There are some bits that could be improved but not bad for a first try. You can view the 3D model online here: https://skfb.ly/6LO8t

We head East from the first cannon and arrive at the second cannon of our dive. The cannon lays across a gully, and tucked in behind it is a swivel gun.

We meet the first dive group here but to avoid overcrowding the area we head North to continue the tour of the other cannon. Following the gully, we end up too far East so turn SW to head back into the centre of the site. We come across a large anchor still marked up with a number 10 from the original SWMAG marking points. We continue south looking for a larger pile of cannon but we must have swam straight past them. With the weather getting worse on the surface the swell under the water is building, we stick strictly to our allotted dive time and put up our SMB to make our way back to the surface. Although it was a short introduction to the site we are all delighted with what we have seen and are keen to get back again asap.

With the second dive of the day blown out, the team head over to the Salcombe Maritime Museum to take a look at the history of the area and view some of the artifacts brought from the site by SWMAG. Back at the campsite later we get introduced to the cannon recording forms from the NAS and practice completing the forms using some cylinders as stand in cannon. The nice weather is holding out and we get to eat dinner outside in the sunshine while we discuss the days events and our plans for tomorrow.

Day Two

Day two dawns and it is gloriously sunny. With less kit to move the trip down to the harbour is easy and we go over our plans for the day while we wait for the boat to arrive. The boat glides up to the jetty, makes a turn and just as it is switched to reverse… Bang!

First signs aren’t good and it gets worse when we find out the prop shaft has snapped. No boat diving today. We unload our gear from the boat as those who know the area work out what to do next. After much deliberation it is decided we will make the hours journey to Brixham, the wind is in the right direction and we are guaranteed to be able to get in. Not the wreck diving we had hoped for but at least it isn’t a waste of a day.

We arrive at Breakwater Beach in good time, the sun is hot, the water is calm and the sunbathers are out. Buddied with Ian and John we head out East across the bay. The visibility isn’t too bad but there isn’t a lot of life out on the sandy sea bed. See Martin’s trip report for the full rundown of sea life to be found as it was pretty much the same today: “common hermit crabs, double spiral worms, eyelash worms, and another similar type of worm buried in the silt.” https://www.marlinsac.com/2016/11/brixham/

A short break for lunch then John and I are ready to go back in. In the hunt for more life and variety I lead the way staying closer to the shore. There’s certainly more life around the rocky reef at the bottom of the cliffs, even if we only get a maximum depth of 4m. We’ve seen large edible and spider crabs, a nudibranch and even a conger eel. Lots of anemones on the rocks and Nursehound egg cases on the seaweed. Arriving back out of the water exactly on the 50 minutes planned we de-kit quickly. We are heading back over to Hope Cove near the campsite to record a cannon that had been previously raised by the SWMAG members.

Using the recording sheets we had been introduced to on the previous night we worked in two groups to record the cannon measurements. Tom gives us some good pointers on the best order to take the measurements underwater to avoid too much travelling that could disturb the seabed and waste time. Good buddy communication underwater would be essential to get accurate measurements. We then compare the measurements to see how accurate each team has been. Finally we each have a go at taking video to use for photogrammetry. Sadly the video I take doesn’t work well enough to get a decent model, in review I think this is due to marks on the camera lens and the bright sunshine ruining the shots. Still good lessons to learn and something I can avoid next time.

It’s the end of a fun day diving, even if it wasn’t what we had hoped to be doing at the start. We head back for a BBQ at the campsite where we review the weekends events and make plans for what would hopefully be a more productive weekend in October on the Salcombe site.