Have a read of this mate:
What happens when you go in the water.
Without a dry suit (and proper insulation) then the initial problem is cold water shock. Your heart rate will go up to 180 to 200 beats per minute - possible chance of heart attack or stroke. Your breathing rate will go up to 60 breaths a minute, you will not be able to control your breathing and so there's a good chance you will take water into your lungs. Cold water shock takes about 3 minutes or so.
By the way, you can reduce cold shock symptoms by taking a cold bath or shower everyday - luvverly.
Swim failure will be the next problem. The blood vessels in your arms and legs will constrict to reduce heat loss in water. The effect is that you will not be able to co-ordinate your arms and legs - your body moves to an almost vertical position in the water and forward headway stops - but because you are moving your arms and legs you are loosing body heat at a much greater rate.
Chances of swimming 20m without a drysuit in April waters (about 8 to 10C) are virtually non existant. Swimming 200m is well....
In fact operating a flare, pressing buttons on a VHF becomes extemely difficult - that's if you don't drop it first.
Swimming in the sea in waves - even small ones - is considerbaly more difficult than swimming in a pool.
And we haven't even mentioned about swimming against a tide or wind and waves or rip tides.
There's a great but old video of Duncan Goodhew and Sharon Davies simming in a pool chilled to 10 degrees. After 10 minutes they have lost the ability to swim - and that's without waves or tides.
Hypothermia officially comes in when your body core temperature drops below 35C (normal is 37C).
Without a drysuit or wetsuit then in 10 C water it is estimated you have about 1 hour of consciousness after that another 2 and half hours if you can keep your airway clear of the water.
With a drysuit or wetsuit the biggest heat loss will be through your head - wear a hat, even a wet one helps significantly! Pull up the hood on your jacket. Makes you more visible (assuming it's bright yellow or similar) and helps keeps the heat in.
Very few people die from hypothermia - almost all drown when their head falls forward in their LJs. I won't talk about buoyancy aids.
The drysuit (with insulation) and wetsuit does increase your survival time but the effects of swim failure and hypothermia will take effect eventually.
By staying with the kayak you make a much larger target for Search and Rescue (SAR) to see.
Even if you can only get your body partially out of the water you will significantly increase your survival time.
And if wearing a buoyancy aid only then there's a much better chance of keeping your airway out of the water.
While it's tempting to self help by swimming for it - it has to be your very last option. Call for help using your VHF or flares or both.
Keith (RNLI)
If that dont change your mind about a drysuit then your suicidal, or stupid
Tell your mate Tman to have a read to, he may be a pr*ck but no-one would want him to die
tightlines, scotty.
