[osprey]

This is how I do it. I'll keep checking this post to see your feedback so maybe I can get some ideas. First of all I STRESS THIS POINT. Never get in between the boat and the trailer to place any cribbage or do any jacking. Stay under the trailer. This way, if the boat falls, you will only be momentarily crushed by the rebound. Survival odds increase by 68.5%.
I start by getting the tongue of the trailer as low as possible, to raise the stern up. Next ,I block the stern with concrete blocks. Make pillars with two blocks alternating direction. Do not trust a stack of single blocks. a 2X4 under the chime works well.Try to end so that the 2x4 crosses both blocks. Now raise the tongue jack as high as it will go and block the bow. Let the tongue back down and the boat should be clear of the trailer. Now you just have to keep alternating the front pillar as you slowly inch the trailer out. If you can get a heavy I-beam to go across two pillars in the bow,that will give you clearence for the wheels ,that would be easier. I have a 4 ton engine hoist that I use to lift the bow as I pull the trailer out. Hope you get the general idea. Be careful. I once used 55gal drums to crib a 27 proline with while I was under it doing bottom paint. I heard a couple creaks now and then, but thought I was ok. 4 days later I went to the boat to find that one drum collapsed and the boat was close to going over. It could have happenned while I was under it!! Not a good thing to learn the hard way.

( The above narative is for entertainment only. Heavy boats should be lifted by trained professionals only....)