Sorry, Julian.
Doesn’t work on a double ender like the Storms and the CBL, I’ve tried it.
Fixed a rope to the two stern cleats, threw it over the stern and, ever hopeful, dived over the side. Action and reaction being equal and opposite, surfaced to a tirade of extremely un-ladylike language and a bottle of sun-cream hurled at my head. (It was factor 50 so quite heavy) The violent rocking I caused during take-off had dumped my wife onto the bottom boards, a situation up with which she would not put. Anyway, found rope, inserted foot, grabbed gunnel either side of the rudder and heaved.
The rope promptly disappeared under the boat propelled by my legs, which were carefully positioned either side of the rudder to avoid the tipping problem. I leave the rest to your imagination. Luckily, I have all the children I need already. Oh, Yes. I cut my shin on the propeller, too. (NB In a seaway that motor is going up and down like a meat cleaver. No way I’d even attempt to board over the stern of a double ender.)
Ideally you really need something at shoulder height to pull on as well as two steps, one a foot or 18 inches below the surface and another at the surface. That way you can get your weight inboard asap to reduce the heeling moment.
My best answer with the CBL is a knotted 25mm rope tied to the grab rail on the far side of the cabin top, tied to a rope ladder on the near side. The ladder has two large fenders attached which seems enough added buoyancy to reduce the heeling and stops your legs going under the boat. You can then, after giving wife due warning, crawl up over the cabin top from knot to knot like the Monster from the Black Lagoon. Hope the crude sketch gives you the idea.
This is obviously useless in an emergency – the only time I have been overboard involuntarily I took the precaution of swamping the boat by rolling it over first. Only had about 6inches of freeboard to worry about!
All this is such a faff that we usually run the boat into a foot or so of water off a nice quiet beach and swim from there. Two methods are employed.
1. Head straight for the beach, drop anchor and feed it over the stern until wife thinks its shallow enough to wade to shore. She will get her eye in after a couple of mistakes. Fix a shore line so you can pull the boat closer in or further out at will. Abuse wife on inability to tie a round turn and two half hitches successfully. This completes the process.
2. If wind roughly parallel to shore (rare but it can happen), drop anchor 10m from shore, let out 20m of anchor warp. To re-board, tow boat to shore, hop on and the wind swings you off again.
N.B. A well kept wife in reasonable physical trim and wearing flippers can tow the CBL at about 1.5 knots, as measured by GPS...until she realises whats going on, of course. Small petrol savings all add up, though.