I was at the King Street boat ramp in Paynesville, and at the time it looked like I had a disaster on my hands, but in fact it turns out to be quite easy to get the keel back into the slot by myself, with only the equipment I had on board the boat, as long as the lift line is still attached to the winch.
The Castle has a full height keel case through the top of the cabin and inclined forward, and a keel with two "horns", lifted by a strong point in the valley between the horns.
This approach should be able to be adapted to any drop keel and keel case as long as they are inclined forward. A helper above water to operate the keel winch would make life easier, but is not essential.
Here's a diagram of the keel in the normal lowered position; the rectangular section at the top is just clear of the bottom of the hull:
The keel has now escaped out the bottom of the hull.
Fortunately the lifting line is still attached (or you've gone for a dive to attach it).
- Raise the keel until the two horns of the top of the keel are just in contact with the underside of the hull, but it is lying randomly (or perfectly at 90 degrees in this diagram) across the hull:
Get out your mask and snorkel, you're going swimming.
- Make a loop of rope about a foot or so in diameter.
- Get your mainsheet (it does have snap hooks on each end?) and fasten the top end to the loop of rope.
- Secure the bottom end of the mainsheet (possibly via another rope) near the centre bottom of the transom, for example to the bottom pintle or the bottom of the boarding ladder.
- Go for a short dive and drop the loop over the rear horn of the keel.
- Come up for a breath.
- Take another short dive and tension the mainsheet, and pull the keel in line with the boat.
Because the front horn cannot rise through the hull, the keel is already tilted forward somewhat.
If you don't adjust the keel winch, then the keel lift point between the horns must remain on an arc of constant radius at the end of the lift line:
- Drag the keel back with the mainsheet, while guiding the rear horn into the slot - this is why the top of the mainsheet is towards the keel - so you can haul on the tail end with one hand and pull the opposite direction on the keel with your free hand. It is surprisingly easy to do, even in 15 second bursts underwater.
- Keep going...
And when the keel is far enough back, the board tips back toward vertical and the front horn just pops up into the slot:
- Remove the loop of rope and the mainsheet from the keel. You may find cutting the loop easier than untying it under water, since you can no longer just lift it over the top of the keel horn.
- Clamber back up on deck and winch the keel into the hull normally.
It really is that easy; although it took me 2 hours to figure out HOW to do it, it took about 10 minutes to actually do on a Castle 650, on my own.