NAS Member Mike Cross reports on his recent experience of diving on the Salcombe Cannons as part of the Salcombe Cannon Protected Wreck Project. Did everything go to plan for the team? Find out here...

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Project participants hard at work learning about cannon surveying techniques

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 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. 

The first fieldwork dates in June were approaching and we received our first bit of homework from NAS. We needed to complete two online e-Learning courses, “Introduction to Maritime Archaeology” and “Underwater Archaeology“. They were both very good courses and formed a great introduction into archaeology in general, as well as just the underwater kind. Both took a few hours to complete so we didn’t have time to hang around.

Fast forward to the end of June and we arrived at the campsite in Salcombe that became our base for the next few days. Mike W brought a huge inflatable tent and Alison from MDMS Marine prepared a spread of BBQ food (so we were hardly roughing it!). We met with the other volunteers and the SWMAG members over food, before John from the NAS gave us a demo on recording an underwater site; this was a practical exercise intended to build on our online learning. The day came to an end with us chatting to the SWMAG team about their diving experiences on the site, and everyone was excited to get out the following day to see it for themselves.

Day 1:

On the first day of diving we met the boat and our base for the coming few hours, Falcon 2, in Salcombe. The van was unloaded and everyone stowed their gear on the boat in preparation. The wind was blowing, and the weather was getting worse, which meant there was a  chance we would only get one dive in. As we set off from the haven of Salcombe, the swell began to build, and crossing the bar turned in to an exciting ride. As we arrived on site, we received confirmation that there would only be one dive today, and a time limit of 50 minutes. Though it wasn’t all bad news, as the weather was looking to be much better the following day, and offered a much more promising dive. Armed with our cameras and a map of the site, we jumped in to see the wreck site for the very first time. After descending a long shot we were pleased to see the visibility below hasn’t been affected by the waves above.

The team enjoying a cup of tea and a briefing before their first dive of the day

I was buddied with Mike W, as I have dived with him before. We were the second group to dive and were very pleased when it was our turn to follow the shot down to the first cannon. From there on, I was 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, made it much easier to find our way around an unknown site.

I had played with photogrammetry previously and it seemed like a great opportunity to get some practice in. I did a quick scan around the cannon hoping to get some tips from Tom (MDMS Marine) on what I can do to improve on the future dives. While Mike photographed some other interesting looking artefacts, I decided to try out the GoPro I’d been loaned for the dive. This model only had 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. Though I was told this could help with identifying who had taken the videos after a dive, I don't think it will catch on.

Mike's accidental underwater selfie on his Go Pro

Next, we headed East from the first cannon, and arrived at the second cannon of our dive. This cannon lays across a gully, and tucked in behind it was a swivel gun. We met with the first dive group there, but to avoid overcrowding the area we decided to head North to continue the tour of the other cannon. Following the gully, we ended up going too far East, so we had to turn SW to head back into the centre of the site, where we came across a large anchor still marked up with a number 10 from the original SWMAG marking points. We then continued south, searching for the larger pile of cannon - but we must have swam straight past them! With the weather getting worse on the surface and swell under the water building, we stuck strictly to our allotted dive time, and put up our SMB to make our way back to the surface exactly as planned. Although it was a short introduction to the site, everyone was delighted with what we had seen, and we were keen to get back again as soon as possible.

With the second dive of the day blown out, myself and the team headed over to the Salcombe Maritime Museum, to take a look at the history of the area and view some of the artefacts brought from the site by SWMAG. When we arrived back at the campsite later on that day, we were then introduced to the cannon recording forms from the NAS, and practiced completing them using some cylinders as stand in cannons. Thankfully, the weather decided to improve, and we were able to eat dinner outside in the sunshine, as we discussed the experiences of the day, and what plans we had in store for tomorrow.

Team photograph outside the Salcombe Maritime Museum.

Day 2:

Day two dawned, and it was gloriously sunny! With less kit to move than the previous day, the trip down to the harbour was easy, and we went over our plans for the day while we waited for the boat to arrive. The boat slid up to the jetty, made a smooth turn, and just as it is switched into reverse... Bang!

First signs weren’t good, and things took a turn for the worse when we found out the prop shaft had snapped – which meant no boat diving. We unloaded our gear from the boat, as those who knew the area well hatched a plan of action. After much deliberation, it was decided that the team would journey across to Brixham. The wind was to be in the right direction there, and we were guaranteed to be able to get in. Though it wasn’t the wreck diving we had hoped for, at least it wasn’t a waste of a day.

We arrived at Breakwater Beach in good time, the sun was hot, the water was calm and the sunbathers were out. Buddied with Ian and John, we headed out East across the bay. The visibility wasn’t too bad, but there wasn’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 that day: “ common hermit crabs, double spiral worms, eyelash worms, and another similar type of worm buried in the silt.”

Divers leaving the water at Breakwater Beach, whilst sunbathers enjoy the welcomed appearance of the sun.

After a short break for lunch, John and I were ready to go back in. In the hunt for more life and variety, I lead the way, staying closer to the shore. There was certainly more life around the rocky reef at the bottom of the cliffs, even if we were only able to get to a maximum depth of 4m. We encountered large edible and spider crabs, a nudibranch and even a conger eel. There were lots of anemones on the rocks, and Nursehound egg cases on the seaweed.

We arrived back out of the water exactly on the 50 minutes as planned, after a quick de-kit, we headed 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 gave us some good pointers on the best order to take the measurements underwater, in order to avoid too much travelling that could disturb the seabed and waste time.

Good buddy communication underwater is essential to get accurate measurements – so once we’d finished the dive we then compared the measurements to see how accurate each team had been. Finally, we each were able to have a go at taking video to use for photogrammetry. Sadly the video I took didn’t work well enough to get a decent model. In review, I think this was due to marks on the camera lens, and the bright sunshine ruining the shots. Still, this was a good lesson to learn for next time, and now I know what to look for next time. I felt as though the photogrammetry of the cannon site I did on the first day came out rather well. There are some bits that could be improved but not bad for a first try! (see below)