Night swimming in night glow

On my bucket list is swimming in bioluminescence. I have seen glowing waters in foreign lands narrated by Sir David Attenborough, I had no idea it also appeared in Devon.

There’s a lovely full moon swim group. They meet and swim under every full moon with a fire ready to warm you as you dress. There’s food and chat and always nice people. Mind, it’s tricky to find clothes and even tricker to get dressed afterwards. And it doesn’t seem to matter the time of year, it is always colder than you think.

Bioluminescence in August & September

The Full Sturgeon Moon named due to the number of sturgeon fish found in the Great Lakes region around this time of year. We should stick to our own name I think, no sturgeon fish in my sea right now, so let’s say the Barley Moon, Fruit Moon, or Grain Moon. It was the last super moon of the year. It had been a hot week, so I’d been at the beach most evenings, with the moon promising to be a corker, ranging from purple and hazy to orange.

The night of the swim arrived and due to miserably, whiney son, I ended up having to leave, come home, put miserable child in the shower and eat a bowl of left over curry. Watching the most glorious moon from the window. The next morning I heard tales of the most magical bioluminescence swim.

We went again the following night – happier son and I – spending the evening playing in the sea with friends, then we sat and waited patiently (with a bag of crisps) until the beach was near deserted and dark.

Tips for bioluminescence swimming

• Wait until it’s really dark.
• Take clear goggles.
• You probably won’t see it from the surface.

We stood – well I stood Will hopped about around the water’s edge – and we waited.

We waited until we couldn’t see where our bags were on the beach anymore. The moon didn’t put in an appearance. Then Will pointed out, where the waves were hitting the breakwater, it was glowing a bit more than the other waves, he’s an optimist that boy (like his mother), but I wasn’t convinced. I figured it was the light bouncing from the promenade lamp above. So given the advice that you could only see it underwater (I don’t think I would have done it otherwise), I thought I’d have a quick look before we went home.

By now, I didn’t want to get in the sea it didn’t look appetising, it wasn’t beautiful and flat, but we’d waited this long…

My son continued to bounce on the beach “I’ll be back in the minute!” and I waded a little, pulled down my goggles and dived down. The only way I can describe it is like your fingers are sparklers… and as they move through the water they explode with flecks of white light, bright, which float away. White floating lights that lit around me as I moved “Whoop!” I ran up the beach, stripped off my son’s t-shirt, put the goggles on his face and told him he had to get in, pants, shorts and all.

I don’t think he’d really believed me – not sure I had believed me either – he ducked and dived, swam, clapped and stamped his feet until I requested ‘my turn’. The moon came up firey orange to top it all off. It was magic.

So these are the things I know and don’t know:

• It’s ticked off my bucket list but I need to do it again.
• The sea needs to be warm.
• It’s plankton that has the bioluminescence.
• There can’t be strong light – eg it’s better on a new moon (or in our case a low dark orange moon).
• We went at 10pm (August), it had switched from gloomy to dark, 10.30pm might be better if you can wait.
• You can’t see it from the surface, we only saw it underwater (until our eyes acclimatised).
• Clear goggles are king!
• I don’t know if it needs to be sunshine in the day time to give them a charge. I’m thinking my garden lights. (I didn’t take biology at school, I had to take combined science.) Someone else, I’m hoping, will know this.
• You can’t see each other in the water, or the land, so think about putting a light or something back on the beach. A light in a tow-float might affect the ability to see the glow.
• Some patches were more bioluminescent that others.
• Because it’s so exciting it throws you off time and space and location, mind how you go!

I’m hope you’ll have a chance to see it.

Magic.