Magic Seaweed explained for Sea Swimmers

Brilliant Blog by Freyja Hunt – how to read magic seaweed to aid sea swimming choices

This is a brilliant blog by Seabird Freyja. Everyone has a different favourite forecasting app that they use to see if it is safe to swim. The most commonly used app is Magic Seaweed that was designed for surfers see what swell was approaching but it can be used to look at sea swimming conditions too!

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Magic Seaweed (MSW) surf report provides a seven day forecast of sea conditions. Here’s a guide to understanding the data so you can get a better idea of what to expect before heading down to the beach.

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Surf

This is the first column in blue. In Brighton and Hove, this is essentially the height of the shore break (or the white bits that can knock you over). This will give you an idea of how difficult it will be to enter and exit the water. MSW is designed for surfers so the measurement used is that of the surfable wave rather than the total wave height. For us sea swimmers it might be worth adding a little extra on to this measurement.

It is worth noting that the value given is the average height. 1 wave in 23 is likely to be twice the average height and one in 1,175 is three times the average height. Therefore, it is worth taking this as a rough guideline and always be on the lookout for larger waves when getting in and out.

In terms of height of the shore break, my rule of thumb is anything above waist height is capable of knocking me over.

 

Swell

Swell – listed in the second column – is the height of the waves once you are past the shore break. A big swell can be a lot of fun as you bounce around above and below your swimming buddies.

The next column gives an indication of the wavelength, or the time between the crest of each wave in seconds. The longer the time, the gentler and more undulating the waves will feel. Conversely, shorter times between each crest means the waves will come more frequently and you may be more likely to get a mouthful of sea water.

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The black arrow to the right is an indication of the direction the swell is travelling. If you are doing a point to point swim, this is worth bearing in mind – if the swell is travelling in the same direction as you, it will feel like it is pushing you along. If you are swimming into the swell you will again, be more likely to get lung-fulls of sea water.

 

Wind

Wind is the main factor influencing how rough the sea is going to be. The stronger the wind is and the longer it has blown for, the larger the swell is likely to be.

The right-hand number column denotes wind speed. The larger number being the steady wind speed, and the small number being the gust speed. The arrow shows the direction the wind is travelling in. In Brighton and Hove the prevailing wind is South Westerly.

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It is worth considering that MSW doesn’t factor in local sea breezes. Sea breezes are caused as the land changes temperature faster than the sea. For example, in the morning the sun heats up the land quicker than the sea. This triggers the air on the land to rise up and and cooler air is drawn in from the sea to replace it. Sea breezes are generally onshore in the afternoon (as the land heats up and air rushes in from the sea) and offshore in the morning (where the land falls below sea temperature overnight and air moves from land to sea).  You might therefore expect the wind to be slightly stronger in the afternoon than denoted on MSW.

 

Tidal Information

Magic Seaweed also shows the times and heights of the high and low tides. In Brighton and Hove, low tides generally vary between 1 and 2.5 meters and high tides between 5 and 6.5 meters above chart datum. The difference between the two is the tidal range. The tidal range has an effect on currents – the larger the tidal range, generally the stronger the currents will be. The tidal range during spring tide in Brighton is around 6 metres.

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In a nutshell

The first column is the height of the shore break and gives you an idea of how difficult it is to enter and exit.

The second column is the height of the swell and tells you how bouncy it will be once you are in and past the shore break.

The third section tells you wind speed and direction – or the best direction to swim in to avoid getting a mouth full of sea water.

The box below informs you of the times of high and low tides and the tidal range. From this, you can have a go at working out the direction and strength of the current.

 

See, didn’t we tell you, a brilliant blog. Thank you Freyja for allowing us to host it on our site. I use Wind Guru, Nautide and Imray too!

Come and join us in the sea, you know you want to!

Come and join the Salty Seabirds for a swim on Wednesday evenings!

I watched my partner sea swimming for years thinking he was a bit bonkers (while seeing clearly how good it was for him) before I took the plunge and discovered it was for me too. You can see how it benefits the smiley swimmers in the pictures but you still feel hesitant about actually taking the plunge…

As part of Mental Health Awareness week this week the Salty Seabirds have come together to put together various events – one is our new Wednesday Evening Swim – the first one very much aimed at encouraging newbie swimmers to come and try a dip with us.

We are a friendly, inclusive bunch, open to ALL who want to swim/splash/dip/bathe with us. Visible female bias in the shared photos and chat we know but men very welcome, honest!

So, to practicalities. Now it is a bit warmer, what do we actually need to get in the water apart from our swimsuit (not expecting anyone to skinny dip for their first swim!).  The real answer is nothing. Warm layers for afterwards are essential so that you don’t suffer from the cold you will inevitably (it’s the good bit, I promise!) feel. There are also a few other bits of kit that make it much more do-able – you can do it without them as some choose to but it can be the difference between putting you off and you getting in and enjoying yourself so I have tried to pare it down to the basics:

  1. Swim hat; to limit the ice-cream head effect, support pain free handstands and keep hair (relatively) dry to protect against wind chill on wet hair. Having said that some of us insist on dunking the head before getting out for the full cold rush/re-boot effect.
  2. Large towel or changing robe; as we change on the beach these can protect against wind chill and flashing your arse to passers by. We have had a few dressing gowns recently which do the trick nicely.
  3. Warm layers for afterwards; woolly hat, thick sweater etc. Easy to put on dampish skin.
  4. Neoprene socks/boots and gloves. Many of us have ditched the gloves by now but not the boots. Decathlon have them or you can find them online (Some folk are fine without them it has to be said.
  5. Hot drink: not totally essential but very helpful; (using a cup as a hand warmer great tip)

Any other tips please feel free to comment below. If you want to try before you buy gear message us in the event page and we can see about lendings…people may have spares hanging around…

For more tips and information about beating the cold and keeping warm post-swim see our older blogs here and here.

I will bring the biscuits – see you next Wednesday!

Author: Seabird Cath

A Seabird Haven

Seabirds swimming in fresh flowing water at Wallers Haven

Wallers Haven – Seabird on tour, inland!

Earlier this summer I was attending Camp Abyss with some of my favourite people in the world; close family and oldest of friends. Sweltering in the heat of high summer and stuck in an exposed, treeless field for the last three days, we needed to cool off and get wet. I turned to my new favourite discovery; (yes the one I’ve been banging on about for ages) the Wild Swim Map and the Wild Guide and found out that Wallers Haven was our nearest swim spot. Hooray!

It is a little difficult, to say the least, to match the spot on the road to the description given. However, we parked on the side of the (very fast) road, waited for a gap in the traffic, then headed over to the bridge to investigate. Unfortunately, we ended up taking the most difficult route, which turned into a battle with nettles and one of our party almost falling down the side into the river.  Don’t do that as there is ‘proper’ access via a path a bit further up the road each way!

Stumbling on, hotter and grumpier by the nanosecond, we eventually rounded the concrete jetty described in the map. It really is the most beautiful spot. Peaceful and surrounded by countryside, with Weeping Willow trees dangling down over the silky surface of the river. Mineral tasting water, refreshingly cold in the heat of the day. My first river swim! Having been stung by nettles, almost falling into the river and spotting a ‘snake’ on the surface of the water, one of our party stated that they were just there to watch.

However, it proved inviting enough to get all of us in and having the absolute best free fun that there is to be had! This despite our varying levels of confidence and anxiety about being out of our depths etc. Some stuck to the edges for a quick float, others dived or jumped in and generally messed about. A perfect spot full of simple pleasures. We all returned to the festival invigorated, energised and much, much happier, all fully converted to Wild Swimming too.

We would love to hear of your favourite swim spots in the comments.

Author: Seabirds Catherine

Tips for warming up after sea swimming

“After drop” is common after swimming in cold water; you get out and feel fine, and then you start to get colder, sometimes growing faint, shivering violently and feeling unwell.” (Outdoor Swimming Society) 

Learning to head off the after drop is a key part of continuing to swim in cold water all year round. While in the cold water you can be lured into a false sense of security (numbness!) and stay in for what turns out to be too long. With practice you learn your limitations and just how cold you are going to be about 10 minutes after getting out. You then moderate your swim times and get out before you feel you have to. Then the key is warming up – slowly. If you have a hot shower, for example, the blood can run from your core (where it is working hard to maintain your core temperature and keep you alive!) to your skin and actually make your temperature drop along with your blood pressure – potentially making you feel faint and ‘stinging’ your skin.

Tips to warm up after you get out of cold water: 

  • Get dressed as soon as you can. Preferably starting with the top half of your body.  Use a haramaki. As you start to warm up blood starts to recirculate in your extremities and peripheral blood vessels, cooling as it travels. You can lose up to 4.5°C from your core temperature so a haramaki is great.
  • Use a robe or a sports cloak to get dressed quicker and protect you from the windchill as well as your dignity.
  • Put on a hat and gloves and have some tea from a flask you brought with you!
  • Put on lots of layers. Haramaki, gloves, hat, thermals.
  • Sip a warm drink: this helps warm the body gently from the inside.
  • Eat something: sugar will help raise body temperature so have some cake!
  • Sit in a warm environment: chance for more tea and more cake with your fellow swimmers….
  • Walk around to generate body heat. It can take some time to warm properly. Running up and down the beach while waiting for your friends-who-faff can help.

For more information about acclimatising to cold water, the benefits and the risks go to the Outdoor Swimming Society 

If you have any good tips please add in the comments 🙂

Author: Cath Seabird