I think for the most part you are launching with a crane or travel lift at 4'. The vast majority of ramp launchable sailboats I've seen are either swing keel, ballasted dagger board, full keel, shoal keel, water ballasted or unballasted usually around 3' or less. I'm sure there must be some steeper deeper ramps around if you hunt around for them though. Launching at high tide might help.
Opinions seem to vary. A 4' keel is strictly crane launchable. Having figured out that my boat has a 4' draft, rather than 4' keel, that changes things.
Looking at images of normal 4' draft deep keel S2's, I am guessing the deep keel models have an ~30" keel yielding a 4' draft. Unfortunately all I am doing is guessing.
Having to go on the opinions of others, it seems that only a small percentage (maybe 10%?) of ramps are built to accommodate a 4' draft.
I am not the only one who has confused draft with keel....I have to take most opinions as being "unverified".
My trucks lift, 4WD, and 37" tires may give almost a foot of "additional draft capability".
Isn't $300 a typical fee for a crane launch?
I will have to get my boat on the hard for a couple days so that I can properly measure and adapt trailer. I am currently figuring $500-$600 for that. Sound about right?