HAving done this, he must learn quickly that the renovation or rebuilding of a boat is a multi year task that is accomplished ALONE. You can give him the list AND an estimate of the time involved. If its as bad as you say, itll be a many year project and he will either learn the necessary boat building skills (Wood or glass?), and mechanicals (Engine overhaul or reset a new one) or he will die.
My project was a hulk of a lobsterboat that was destroyed in a storm crash. It needed the entire above decks and some new hull and transom work. IT WAS almost 12 years in the making and it was a lonely passion. I had checkmarks and schedules and CALENDARS hung out with the years ticked off.
When it was done it was a beautiful one design with modern technology like side thrusters and marine electronics for deep water "passage making"
I used it for maybe 8 years and sold it because I needed money for my business .
I never counted on anyone to have the same "ownership" invested as did I. I never even trusted anyones skills unless I paid for em. Building a boat is not a project that involves paying guys with beer unless you dint care how she sits the water and plows ahead in high water. If he does he WILL wind up with a kind of crap that the guys in the beer commercial had(no criticism of you but when you get frustrated, you can just go home--he cant).
Im talking about detailing lines and chines by drawknife and spokeshave and lovingly covering the whole thing with bubble free glass fibre and tip and roll painting the dear thing so that the lines gleam like a single unblemishhed surface. Its either that or tell him to just take it out and use it for a planter.
You should just be there for your friend to keep him from torching his boat (There will be these times when he will feel that , the only way out, would be to burn the whole thing, knock down the boat shed that he will have to build around it and just start a new life somehwre in Ohio).
My boat was almost 40 ft LOA. It could be confused with a Hinckley TAlaria except I had the pilot house lower and raked back so it looked really "stealthy" I loved that boat and was real proud in a way that only building a boat can derive. It cost me a hell of a lot in money and time (I had a thread devoted to sailing it . It went on for about 4 years onA2K).
A boat is like a journey to MEcca, you get no more credit by making it a road trip with friends. He must learn or fail. Its in his hands entirely. SHow him this and let me assure you that, unless this is a small rowboat,It will become his life for several years (My wife had a dinner party quip that she would make about boat building . She said it ws about 6 months per foot of wetted surface.
Tell him good luck and to take his estimate for costs and time and multiply them by 1.5