Safety: Light and visibility and men in black – swimming with and without a safety buoy

All these “men in black” swimming open water – do they know how invisible they are while swimming ?


You find the answer “where the swimmer is” at the bottom of the post.

Can you spot the swimmer in the image above?  I saw this guy last summer. He came swimming from left in black wetsuit. It was right before Tjörn´s triathlon so I presume he was doing his last training session. I had some coffee and then looking back over the sea he was lost for several minutes. I was amazed….I knew he was there…with his red cap.  Where did he go? When he reached the jetty I could see he had red cap. He probably thought he was safe.

I did a simple experiment last week to recreate this scene.  I do not think the swimmer is very visible in any of the scenrious. Sadly the autofocus failed initially at first sequence but sharpens when the “fun” starts.

Due to the following study vivid green and orange have best visibility at sea. Red, yellow and blue is not good at all. Sadly I do not think that had any other neon or vivid color than green in this test. I am curious about neon pink for example

Study about colors at sea: Mustang Survival On-Water Visibility Study>

Remember that the environment affects what the best choice of color is. Once I “lost” a friend for 15 minutes. He was wearing a vivid green swim cap. We were swimming in a lake with fresh green trees and lawns and the shores. I couldn’t see him despite I really scrutinized the water and the landscape.

Do you want to swim without getting stung by jellyfish?

A orange swimcap or safety buoy can be almost “invisible” if you swim in areas where there use to be fishing nets or in a habour with orange buoys. Once I swam close to the shores at a small island very far out from land. A local fisher man presumed I was just that fishing net he was looking for. He realised his mistake luckily in time.

For your safety


  • Wear a safety buoy and swimmer cap in different vivid color
  • Avoid green if you swim where the shores are green
  • Avoid especially wearing only vivid pink or orange (or whatever color boat buoys have  in your area) while swimming.

Compare this orange swimmer´s buoy with the fishing net buoy. Imagine the similarities at far distance especially since when swimmers cap is black