• Stops the lifejacket riding up over your face or even head, by wearing a crotch strap it enables you to float better and keep your airway clear of the water. 
• Keeps your lifejacket in a safe and correct position 
• No waste of energy holding lifejacket down
• Means the waist strap doesn't have to be quite as tight to hold lifejacket down - particularly relevant to those whose waist is larger than their chest.. 
• If you fall in from any height with no crotch strap, depending on the make and model of lifejacket, the inflated life jacket can completely come over your head with the force of impact. Wearing crotch strap would keep your lifejacket in place and in the correct, safe position.

Even in the height of summer, waters around the UK are quite cold and if you accidentally fall in your first reaction is to gasp with shock. This short-lived reaction means that you re uncontrollably and indiscriminately gulping for air, so the closer your mouth is to the water the re water you’ll gulp.  A crotch strap will enable you to protect yourself from this eventuality (particularly when fitted to an automatic or hydrostatic lifejacket). 

If you need more persuasion watch the brief video below: