As someone who has spent more time in and around water than most, I would say that each person really needs to consider their own resilience to being dunked in cold water in a shocked / stressed way.
I recognise that as I’ve got older my resilience has dropped from top level to almost nothing.
Loss of breath, tightening in the chest, and uncontrollable shivering set-in almost immediately. It’s just a question of how long it takes to recover to a point of being somewhat capable again, if at all.
Basically I Don’t think in the cold months the average unfit, non hardcore, non outdoorsy type can guarantee to make a decent swim along the raft painter and then pull themselves in.
An immersion suit or even sport dry-suit could make all the difference in those circumstances.
My sport drysuit can be worn over normal clothes comfortably and I have been neck deep in January/February in it with no issue at all.
I haven’t needed to wear it flying yet, but have it (it is used for other stuff) to hand incase I decide it will help.
I haven’t tried an immersion suit but have seen plenty of them around. To my opinion they appear robustly made and very ‘up to the job’ they also appear a little bulky and possibly a bit uncomfortable, especially if imagined in a light aircraft cockpit.
My drysuit is intended for muppets like me who wish to windsurf, kitesurf or jetski in the middle of winter.
I have this one, but some are even lighter.
I’m intending to buy a used one for the wife. Even an old possibly a little leaky one can be patched perfectly well enough to keep you warm and dry from the aircraft to the raft and in the raft. Just not to remain in the water.
As Peter said bobbing in the water is no real use except on the warmest sea day and with your PLB held above your head
I think if you were to be able to exit the aircraft onto the wing and (in a luckily ideal scenario) climb straight into a raft, you wouldn’t need the suit. But in all but a sunny day you may still get cold quite quickly (thinking channel, north sea, not Med)
It’s all about knowledge and using it to make choices you can live with.
I have a high wing and am convinced we would need to allow the cockpit to fill before we could open the door and exit. If we opened the door 1st, 1 may get out, prob not due to water force, but a second definitely wouldn’t.
Our plan is to carry masks to alleviate not being able to see underwater and reduce spluttering from water up the nose. This is briefed and should help with panic (yeah right! But we hope) The plan is that once its submerged to the wings, it will float for long enough to exit. Then into the raft.
The best defence of course is 10 to 12k (within gliding range) on a channel crossing.
@GA_Pete Thanks for that full explanation. I have always crossed the channel in a twin in the past few years. This year I haven’t validated my MEIR and am looking at the best safety equipment for my wife and I to wear/carry if we should do so in the future. Perhaps even in a ULM🤩.
You’ve given me a lot to think about.
The UK CAA have made the remark (my Google-fu fails me – I can’t find it right now) that they have not seen any evidence that a drysuit has saved any lives during a ditching in the waters close to the UK, but in the Irish Sea/English Channel rescue does tend to arrive fairly quickly. In one ditching where I know the unfortunate owner of the plane, they were rescued before the plane even sank and before they could get into the life raft.
You have to be careful that you’ve put your drysuit on correctly. On a dinghy sailing course I did someone who had a drysuit somehow managed to get it wrong, and after capsizing found it had filled up with water. Of course in that instance it was extremely funny (watching him going up the boat ramp in a drysuit filled neck deep with water, the weight was incredible and he struggled to walk till he let it out via the ankles) but in a survival situation this would be nearly like having no drysuit at all and would make it impossible to board a liferaft. On the other hand I didn’t have such a problem with my drysuit and despite getting the dinghy completely upside down on several occasions, I stayed warm and dry throughout.
So if you’re going to get a drysuit, make sure you use it a few times to make sure you know how to use it, and have confidence that you can put it on in such a manner that you do in fact remain dry.
GA_Pete wrote:
The best defence of course is 10 to 12k (within gliding range) on a channel crossing.
Affirm 
The figure sounds (or reads…) a bit high, though it is of course highly dependant on your glide ratio, and the place where the crossing takes place. My last one wasn’t too long ago, between Calais and Dover, at FL64 about to scratch the sacrosanct A CAS, and the glide circle of my SD had us in shore gliding distance for most, but for a 1 minute break.
These gliding distance tools as provided in different programs and devices, are, if programmed correctly, a great help in SA.
Call me complacent, but I keep my Typhoon survival dry suit for longer and more desolate, colder stretches of water…
And shame on me, I even left my raft at home (efficiency is always part of the mission 
) last time we crossed the channel. OTOH it was on board for our latest Genova – Calvi crossing a couple of weeks ago, as the overwater leg is much longer than the mere channel.
I really don’t think ditchings occur in the small time window during which you are out of glide range.
They happen mostly due to too much air in the fuel tanks.
There are easy strategies to reduce the risk e.g. if I am flying EGKA- LFMT I will fly along the UK coast for a few mins, then at 5000ft set cruise power and then head south. Smart ferry pilots do the same; a large % of their jobs (in piston GA) are old pieces of junk, often abandoned for months, so they never pick up a job right on the coast and head out over the Atlantic. They start a few hours back, checking oil burn, etc.
A C177 landed in the Med just off the coast of Fréjus this morning. All 4 occupants survived. Not clear if it was LFMD traffic.
I highly recommend these for a comfortable wear all day, built for purpose, life jacket
Mid level pricing and designed with aviation in mind
I bought four of them around five years ago and both myself and the various passengers over the years have found them to be very unobtrusive.
Not clear if it was LFMD traffic.
A little late to the event here… yes it was. It was parked outside my hangar for a while (with its previous registration, T7-SAR). I heard about it from someone at the hangar, who said it was fuel contamination. From what little I’ve seen it was more likely, as Peter says, “too much air in the tanks”.
There was a Twin Comanche that went down in the sea just off the end of the runway about a year ago that almost certainly WAS fuel contamination, though they conveniently never recovered the wreck to be able to investigate. (That was someone who shares my hangar too).
