All ya need...

I've wanted to do something like that, but never had the balls to try it.

Hulls sure are strong.

This one is more robust than one normally sees, but its under a big, twin engined boat.

OK, I'll bite. What is the purpose of the wood block? The only thing I can come up with would be to take weight off the trailer tires while it's garaged/stored.

To have the boat off the trailer all together.

How would you lift it off the trailer? Sling it? Fork lift from the rear?

You could pull it off. You can also drop the front of the trailer, block the transom and then raise the front of the trailer and block the keep at the bow.

Of course, I have never done this, but it is the way I was going to do it wh there was going to be a need with the previous boat.

Last time I needed to get it off the trailer for a period of time a rented a transient slip and left it in the water.

SB, I thought about your first method, but no matter where you block the bow it's going to make it difficult to pull the trailer out from under the boat.

Based on what I've read, you attach the stern via the lift eyes to a tree or other object. Slowly pull the trailer forward a foot or two and block the stern. Continue pulling the trailer out blocking as you go. You might have to move some blocks on occasion to facilitate pulling the trailer out, but it should work.

If I were to do it I would do the other method and jack the boat up and block it. Move the trailer and reposition the blocks to work the trailer out. It would take some time, but I know it gets done all the time.

Use a jack, but do not drop the boat while doing it. It helps if someone holds the side of the boat to steady it.

For this size boat, use a Travelift.

I have done this several times. It is not too dificult, just pay attention and work with someone you trust.

Lower the tongue, and block the two aft corners. Raise the tongue, and block the keel as far head of the forwardmost crossmember as possible. Now pull the trailer forward as far as possible. Now I used a good jack just aft of the crosmember, and pulled some more. Repeat as necessary until the blocks are aft of all the crossmembers. Done carefully, it is not as bad as it sounds. Use wooden blocks and run the grain perpendicular to the centerline of the boat, so as not to split them. Do this all slowly, on good solid ground. Going back under is the same procedure in reverse.
Fun times.

I didn't pull trailer out but did similar trick of lowering/raising tongue to get our old 17' Procract lifted off trailer to replace center rollers. I only blocked one end at a time as I replaced the rollers.