Winter Swimming

The water temperature drops to as low as 12C near the beaches in February and March, but it is usually one or two degrees warmer further out. Here are suggestions for swimming in cold water and some gear recommendations.

Suggestions for Cold Water Swimming

1. Dress appropriately. Do the same as we do for winter cycling, etc. Pay special attention to the head (neoprene cap), core (neoprene undervest), feet (neoprene socks), and if it is very cold, the hands (neoprene gloves). These are all easy to find online and generally very cheap. (See next section for links.)

2. Be prepared to turn back. When you start, it will feel icy cold, but this should only last a few minutes. We usually swim to the white rock 150 metres off Hayama-koen. If you are not warm by then, you probably won’t warm up. Go back to the beach, finish the swim, and come back another day. 

3. Swim regularly. Related to the previous point, it is best to start with shorter swims when you first hit the cold water, but over the weeks, you will become acclimatised to the cold water.

4. Choose fine days. Swim on sunny days with low wind. Obviously sunshine on a black wetsuit is warming, while wind is very cooling.

5. Swim with a buddy. Always swim side-by-side with a buddy. Keep a constant eye on your buddy, and every few minutes stop and talk to each other. They should be alert and “normal” (not shivering, shaky voice, slurred speech). Do not leave one slow person behind.

6. Stay close to shore. In the case of the Hayama-koen area, stay within the protected bay. Do loops or triangles rather than swimming out somewhere like Ogashima. Once you get out from the protection of Chojagasaki, a seemingly calm day can suddenly become quite windy. Check the wind directions, this will help you choose the sheltered places to swim.

7. Keep moving. Do not stop for long periods of time. Do not wait for slower swimmers, instead swim back to them.

8. Dress quickly. After the swim, get out quickly, undress in a place sheltered from the swim and in the sun, dry and dress quickly.

9. Bring warm clothing. Bring lots of warm clothes for afterwards. Have thermal tops and bottoms in your bag, extra warm layers, a wool hat, and of course a warm jacket.

10. Have a hot drink. It is a good idea to bring a thermos with a hot drink, such as herb tea or soup. This will warm you up from the inside. There is also a vending machine in Hayama-koen selling hot drinks. 

Cold water swimming does not mean you are cold! Even with the water at 13 or 14C, on calm, sunny days you can get very warm if you wear appropriate winter swimming gear. It can also be the most beautiful time of the year to swim as the water is often crystal clear and the views of Mt Fuji are fantastic.

This GCN video has good advice about cold water swimming. 

Cold Water Swim Gear

1. Neoprene Vests: Several companies make thin neoprene vests to be worn under a wetsuit. These make a huge difference in the cold. Zone 3 Neoprene Warmth Vest    Orca Heatseeker Vest   Huub vest. You mist also find a cheap one online, but make sure it is thin (around 2 mm) and there is no zip.

2. Blueseventy Thermal Neoprene Skull Cap: This is a neoprene cap with a thermal lining which seems to work well. The chin strap is longer than other neoprene caps.

3. Blueseventy Thermal Swim Socks: These are the thermal version of the excellent Blueseventy swim socks that a lot of us wear.

4. Neoprene swim gloves: neoprene gloves are widely available as they are used by divers, surfers, etc. Blueseventy Thermal Swim Gloves are specifically for cold water swimming. 

5. Neoprene shorts: there are a lot of brands of "buoyancy shorts" to help with swim training. These also work well under a wetsuit for extra warmth. Blueseventy does these buoyancy shorts.

6. Swim mask: a swim mask covers more of the face than regular goggles. It can help prevent cold water pain around the sinuses. Cheap swim masks are available online; this one works well.

Video: “How to swim in cold water”: GTN has a video which explains the body’s response to cold water swimming and offers advice.