Have you ever surfaced from a dive off a wreck and noticed how along you can be when you cant see the boat? The Diver Alert Flags means that the boat will always be able to see you, even if you cant see it. When stowed, the Diver Alert Flag folds into three, before the flag is rolled around the pole, making it the same length as a 12ltr cylinder. When unrolled, the flag significantly increases you visibility to surface craft.