Single skin fiberglass hull construction info.

very good

ok now we have some answers that we can all work with and you have limited glass experience so we can work on that as well .
the water ballast is nothing new and there pluses and minuses for that and a bulb keel attached to a centre board that can be recess part way up into the boats is a good idea and all the mechanism on deck for rise and fall .
I did mention a sail drive and believe me they are well worth a very serious look at least before you go off looking for wells in your cockpit or ugly stainless steel brackets on the transom !! Have you ever seen a sail drive unit ?? very simple very effective and quite small mostly diesel and really smooth running !!me if I was building a sail boat wouldn't hesitate to have one ! come in a range of sized single cylinder always to the bigger 4 cylinder for big boats !!

 

So you want a trailer sailer? That changes things. The loading and transport are hard on a hull and you probably should go solid skin in way of the trailer lands at least. So far, the boat could weigh anywhere from about 8000# to 2200# depending an how you go about it, and whether its 28' or 25'. I don't know of any boat of trailerable width that has twin berths under the cockpit. You need 9' beam and about 28' loa to get that to work and not look like a shoe box. Look at the old CAL 28. It had twin berths under the cockpit, but you needed two helpers to pack you in there. Ok for kids, though. For a trailer sailer, look at Clipper Marine 26. Also old, but done by one of the best designers ever.

Unless you plan on a very good drop keel, you will be better off with a solid hull bottom that is heavy. That is part of your ballast, and is much better than water ballast since it's density is higher and it is as low as it can get. Water ballast is difficult to get right. I'd pick up a used Macgergor 26X if that's the way you want to go. I doubt you could build anything close to as good on a first try.

It's difficult to guess your budget, but it sounds like you'd need 50K for stuff that gets into the boat and probably another 25k in odds and ends and tooling and storage- stuff that never becomes part of the boat. You can buy a very nice 35' cruiser and five years of maintenance and dockage for that.

I've owned a 38' cruiser for five years or so and my total costs to date are barely 40K. I was talking to a couple in Georetown, Bahamas, and the subject of cruising budgets came up. He said he and his wife had budgeted $8,000 for six months cruising. After a little while, I realized that included the purchase and fitout of the boat, and transport from Canada to Miami, plus six months cruising expenses! Used boats can get you there cheaper and a lot faster.

 

Sorry I don't want an inboard of any kind period.