The OSS’ Laura completes Summit to Sea swim

12th April, 2019

Last weekend saw the OSS’ Instagram Editor and SAS Regional Representative Laura Sanderson complete her Summit to Sea swim of Afon Glaslyn, in Snowdonia. The river stretches 26km from its highest point at Llyn Glaslyn on Snowdon down to the sea. She and her fellow swimmers Dani Hicks and Ruth Bulleyment collected plastic pollution, joined in beach and river cleans at villages, and gathered water samples at four points to be tested for microplastics.

“To prepare for the swim I had been swimming all winter so i was used to the temperatures,” says Laura. “I had been in the pool trying to improve my endurance for one of the OSS event swims and this helped with stamina. We started in the dark at the foot of Snowdon. As I made my way up there was snow on the ground and the lake was very, very cold and the sun was only just coming up. I had to swim out to the centre of the lake and take four one-litre bottles of water from 5-10 cm under the surface. I was sampling for microplastics that are invisible to the eye, in partnership with Bangor University and Dr Christian Dunn.

“As this was the first lake and we had a whole day to go we decided not to start off with head under water and did the old Captain Webb breaststroke. The water had an eerie clarity and you could see single use plastic bottles and coffee lids on the bottom of the lake. The second lake was much much bigger than the second and we decided to wear tow floats, mainly to pick up any debris found and also in case we suffered with any cramp from the amount of time spent in the lake. The sun had come up by this point but it was still very cold.

“That night, we camped along the river bank at Pont Glaslyn. It was beautiful and surreal to fall asleep under the stars and wake up to sounds of birds in the trees. We started this section by scrambling down under the bridge, where the water was fast-flowing. We jumped in and held on to our floats and we were swooshed under the bridge into the deep pools. We knew we had a very long stretch of tidal estuary to contend with and we had the sun on our backs, so we started this stretch with front crawl. After stopping to remove larger items such as car bumpers, agricultural tarp and hundreds of single use plastic bottles, we broke into a leisurely breaststroke.

“As the river opened up there were herons, fish and swans – it was too beautiful to thunder past, so we took our time swimming and noting the different types of plastic pollution. As we reached the end of the tidal estuary, it opened out into vast wetland. Here we swam past egrets and huge fish were jumping out of the water ahead. I felt very fortunate to have been able to experience a waterway from source to sea from a ‘frogs eye view’. It really gave me a greater affinity with the wildlife that inhabits these wild spaces. It was saddening to see huge amounts of single-use bottles and plastic pollution that had accumulated along side the ‘hidden’ riverbank alongside the road thrown from vehicles. People often have an ‘out of sight, out of mind’ attitude but unfortunately it all has to go somewhere and 70 percent of ocean plastic is carried along waterways and ends up in our oceans.”

  • To donate to the Snowdonia Beach Clean
  • Special thanks to Alpkit for sponsoring the Summit to Sea team
  • Find your nearest clean or volunteer to lead your own at or by emailing All Clean Leaders will receive a Big Spring Beach Clean kit, a limited edition SAS insulated Hydroflask, a step-by-step guide to organising their clean, along with support and guidance from the SAS Team.