Do you have blisters when you swim with your monofin?

Do you have blisters because of your monofin practice? Well yes, it happens! The friction that occurs between the foot and the monofin foot pocket is the cause of your worries. A monofin is sometimes uncomfortable. This discomfort is a necessary evil. Indeed when the swimmer presses on his monofin, the monofin must respond immediately. This is why the foot must be correctly maintained in the shoe. This is particularly true for the competitive finswimmer. For the freediver it is not necessary to have the footpocket so tight but it is nevertheless necessary that the foot is maintained and it is therefore possible that you may injure it. Usually these are blisters that can appear on the toes and/or the head of the 1st and 5th metatarsals. 

The surface of the skin allows a certain deformation without causing the slightest injury, but if this deformation goes beyond the tolerance threshold then a blister will form. The skin is made up of three superimposed layers: the hypodermis, the dermis and the epidermis which is the superficial layer of the skin. Following friction in the footpocket, the epidermis separates from the dermis. Normally the dermis rises up to form a blister filled with a clear liquid which is intended to protect the injured tissue from pressure on the wound… but for your poor foot, whose skin has been softened by water, friction has long since torn the skin from the blister which forms the blister. This is actually no worse because it will allow the wound to heal more quickly since healing only begins once the blister has burst and the fluid has gone. 

There are several solutions to prevent the appearance of blisters during your training sessions: 

  1. Use a neoprene slipper (2 or 3mm thick). Not a whole shoe but a half shoe which only protects the toes and heads of the 1st and 5th metatarsal. Disadvantages: if your shoe is already small then your foot will be a little more compressed which in the long run is quite painful because the foot is more difficult to irrigate by the blood and will become all white. If you want to use a neoprene toe cap then it is perhaps smart to take this into account when choosing the size of your monofin’s footpocket. 
  2.  When swimming with monofins, plastic is used! A plastic square from a common plastic bag (not too thin). This piece of plastic should be reusable during your numerous training sessions. Simply wrap your foot carefully in the plastic square to benefit from effective protection. The advantage is that the plastic is not thick and will not add compression to your foot. It will just take care of the excess deformation (elongation) of the epidermis, the one that causes the blister. This is my favourite solution.
  3. The other solution is to protect the sensitive parts with insulating adhesive tape of the “chatterton” type. This allows you to perfectly protect a toe before it is injured or once it is already injured you will have to apply a bandage first to protect the wound and then the duct tape. But be careful not to tighten it too much, otherwise you will make a tourniquet.

Do not use Elastoplast Roll to protect your feet. Indeed, the composition of Elastoplast Roll means that it will form small balls of adhesive material which will become lodged at the very bottom of the footpocket and will cause even more injury and discomfort. These balls of adhesive are almost impossible to remove!

To heal your blister(s), as soon as you have finished training, leave the foot out in the open, having first disinfected the wound with a suitable product. For a small blister you can continue training. The first few lengths will hurt a little but the skin will soften and you will be able to train properly. At the end of each training session, disinfect and ventilate your foot as much as possible. Of course, if you can space out your workouts, it’s better to take care of the blister. For a large, ugly blister, stop training so as not to aggravate the situation and consult a specialist. 

For a competition event I recommend that you don’t wear plastic or neoprene shoes.  Because it seems to me indispensable to be one with your monofin, it must be an extension of yourself. As soon as you move, the monofin must follow you without dead time.  You have to feel everything. I will therefore opt in competition for a slightly smaller shoe without protecting the foot. Protection is useful for repeated training but in competition it’s ONE shot, let’s go! 

Be careful if your monofin is brand new and you’re going deep.  It is possible that with pressure the mechanical elastic properties of the material that makes up the shoe will be altered.  It would be quite unpleasant to find yourself at -90m with a shoe that would lose its elasticity and make you suddenly take one, two or worse three sizes more… Your foot would float in the shoe and to go up from the depths it must be quite stressful.  To be sure of your new monofins, test your monofin footpocket on depths in a progressive way.