Well, Shintullah is on the hard starting her transformation, the bottom has been sandblasted. The yard is recommending they zinc chromate the bottom then coal tar, then bottom paint with high copper paint. Is this the standard way to treat a steel boat? Comments? Agree? Disagree?
To do a steel bottom, the first coating should ideally be applied within a few hours of sandblasting the metal bright. I am not sure if the picture you show is, in the view of the yard, now paint ready but if so I would be a little nervous. It looks ready to apply paint that will be failing soon, but not for what you probably are looking for.
I'm going to re-do Delfin's bottom, probably next year, and I can only tell you what I intend to do. May not be the best and others may have other opinions (count on it), but this is what I will be doing, using AwlGrip's products, which are the only ones I know very well.
1. Sand blast to bright metal to a 2 mil profile
2. Coat within 4 hours (do by sections if necessary) with Max Cor CF. This is supposedly better than Zinc Chromate, which would not be a very high bar. Awlgrip used to make a killer product that isn't available in the U.S. anymore and I am hoping the Max Cor is as good.
3. 24 hours later, apply HullGard Extra Epoxy primer to 4 mils dry (2 coats).
4. no more than 24 hours later, apply HullGard Epoxy primer to 10 mills dry (probably 5 coats).
5. When the last coat of the primer is tack free, apply Awlstar Gold Label to 12 mils dry.
Re-coating a couple of years later can be whatever you want that is compatible with the Awlstar, or you can stick with that.
Except for renewing your bottom paint every couple of years, that should result in a very, very long lived substrate.
Hope that helps.