Sailing Around Cornwall Looking For Cetaceans

Clicks, codas, boings, buzzes and whistles. Just a few of the names we use to describe the weird and wonderful vocalisations from our UK Cetaceans. We have around 30 different species of whales and dolphins spotted around our coast; some resident groups and some rare visitors just passing through.

This summer I was lucky enough to be invited to take part in this year’s Cornish Cetacean Survey with the University of Plymouth - 6 students, 2 lecturers (and a lot of biscuits) sailing all around the Cornish south coast for 5 days.

We surveyed in full sail, shivering with cups of tea in one hand, and binoculars in the other. Or we sat in the sun with fried egg sandwiches out by the Eddystone Lighthouse, spotting soaring gannets. Ok, the sun only lasted for 5 minutes, but still...We lived on a 44.5 foot Dufour yacht, cooking hot meals together for dinner, keeping stocked up on biscuits in every coat pocket, and watching intently for fins slipping out of the water at every hour of the day.

One of the first sightings and probably most exciting for me was a beautiful Minke Whale (Balaenoptera acutorostrata). We spotted it purely by chance, whilst the yacht was heeling up on the starboard side, whilst being huddled up in coats and hats from the chilly northerly wind. One of the crew screamed out “PORPOISE”! Suddenly all of us are stood, poised and holding the railings at the edge waiting for it to show us its fin a second time.

We then get a glimpse of a body that is far too long for a porpoise, a fin located far too close to the back of the animal, and a very pointed rostrum...All of us then screamed, realising it was a Minke Whale which is when someone grabbed the data tablet quickly to input the details as accurately as possible. This Minke was seen about 4 miles outside of Fowey, according to the survey data, we’ve been seeing Minkes roughly in that spot for the last 3 surveys at least.

We needed quite a lot of equipment to carry out the survey; mainly warm clothes, snacks (actually, lots of snacks), binoculars, many ID guides, and a few more specialist kits. One of the pretty vital things we needed for the survey was a 200-metre length purpose-built hydrophone. We towed this whenever it was safe to do so, for as long as possible. When towing; we tried to use just pure sail power as much as we could to minimise the background noise, which wasn’t difficult this week as the wind was excellent for sailing.

We also took with us an onboard monitor set-up that we could hook up to the hydrophone on the deck. This meant that every time any of us spotted a porpoise or pod of dolphins above-deck, we could run down below and allow our eyes to be glued to the computer screen while we waited to see those fateful dashes and dots on the spectrogram. This was also sometimes quite incredible when we had no sightings above deck, but we could see the gentle dashes on the spectrogram screen. It leaves you with the unnerving feeling of being watched.

So every morning at a ridiculous hour, we awoke to the sweet tones of a screaming seagull, coffee being made, or Al turning the radio on as an attempt to wake us up. We would all go up on the deck straight away, helping to get off our mooring or pull the anchor up. The surveying would begin as soon as we had light; 2 of us watching with binoculars and calling out what we’re seeing, and one of us inputting the data. We did this by rotating every hour so that we could get snacks and a cup of tea, go to the toilet, and most importantly helping with the sailing and navigation. We all got the opportunity at helming and navigating with the help of Al, our ever-patient skipper.

The whole team learnt how to use charts, calculate distances, identify buoys, channel markers and not fall over on a very hard heeling boat (well...most of the time!). We got so excited about the first cetacean sighting of the trip, and by nearly a week of non-stop sightings, we still made the same shrieks. Being so close to these amazing marine mammals never gets old, not even a little bit.

To understand more about our UK cetaceans, acoustic and visual surveys need to be undertaken in as many different areas as possible. The surveys are vital to help monitor population levels, observe behaviour and record weather and acoustic data. Lots of surveys are undertaken from land with binoculars but without the acoustics aspect, these are also limited by how far you can see. With our survey method of zig-zagging along the Cornish coast, we can still get to the little coves and inlets where birds and cetaceans are hiding, but also get offshore enough to cover the whole coastline as much as we can. We had the advantage of having the acoustic capabilities onboard to match with the sightings data, and also an AIS (Automatic Identification System) to match our sightings and data with our sailing route.

There wasn’t a day of the trip that we didn’t get a flying visit from a pod of common dolphins, (Delphinus delphis). Whoever was on watch would spot them from 500m or so away. They would come over to the boat and play in the wake for a short while and then cruise away to whatever they had planned for the day.

On the third day, we had a pair of common dolphins leaping out of the water on either side of the boat, in what I could only describe as playing. They were so beautiful, staying with us for maybe 20 minutes! Interestingly, they seemed to see us from further away and swam over to investigate what we were up to. We can only hope the hydrophone picked up their chatting while we were peeping over the edge watching them.

The whole experience was absolutely amazing. It really made me grateful to have the Cornish coast as my back garden, and also go to University in such an awe-inspiring place. Seeing whales and dolphins somewhere I have lived for most of my life is so much more special than on any documentary, makes you appreciate our home coast down in the south of England, and all the really special creatures hiding on our doorstep.

If you are lucky enough to have access to the sea, any sort of vessel, or live close to the coast, make sure if you see any marine mammal, to give them plenty of space and be respectful of sound and engine noise!

Follow the ‘WISE’ guidelines from the Marine Management Organisation by maintaining 100 metres distance and turning off your engines if any wildlife approaches you. Maybe even consider doing the British Divers Marine Life Rescue (BDMLR) training, Marine Mammal Observer with Organisation Cetacea (ORCA), or even just joining some local wildlife groups on Facebook! I did both courses years ago now and absolutely loved them, would totally recommend them.


Written by Bryony Pearton

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