1972' Seafari 25 Rebuild Project

[Glaucus485]

Maybe its a shot in the dark but here are my thought for what they are worth (I am all ears for feedback)

Add a 40 gallon water tank (constantly filled) center and low forward and two (2) maybe 75-85 gallon fuel tanks down in the center tucked to the face of the main v berth or even further forward (the current tanks are about 12'' tall sitting 3'' below the main deck and ending only about 9ft from the face of the transom (where the footwell begins). The existing tanks rest on a raised subdeck below the main deck so lowering them further would therefore lower my CoG down in the hull as well. Removing the cabin would also in theory lower the CoG further down in the hull.

[Capt Chuck]

There is a extreme differance in the Deadrise from the 25' Seafari & the 23' CC ! A layover schmatic of the two hauls is on this sites" previous posts, which I can' t locate at this point. Advise you to research further.

[Xcomunic8d]

Originally Posted by Glaucus485

The existing tanks rest on a raised subdeck below the main deck so lowering them further would therefore lower my CoG down in the hull as well. Removing the cabin would also in theory lower the CoG further down in the hull.

I sincerely wish you well but IÂ’ve given up trying to even put outboards on her. Let alone what youÂ’re toying with. Even my local merc dealer whoÂ’s played with these said donÂ’t do outboards. Go I/O. ThatÂ’s astounding to me.

I’ve torn this area out. There was 1/2” piece of plywood and some float foam down there. The rest is a. Extreme v with stringers. You won’t be able to lower the tanks much. Your biggest issue is adding/moving weight forward without making it ride like a dog or exceeding it’s weight recommendation. Checkout terrys outboard cg tool. That’s what won me over.





Raised my center stringer to make a flat shelf for tanks. Not pictured are some mini bulkheads underneath for lateral support. But not to keel for drainage.



I said all you said about 5yrs ago. Fresh water tanks (this will be hard unless you do a bag) , lead ingots, hard top, trim tabs. I even have valves to pull fuel from stern tank first. ultimately gave up and decided to do a restomod.

[Glaucus485]

Originally Posted by Capt Chuck

There is a extreme differance in the Deadrise from the 25' Seafari & the 23' CC ! A layover schmatic of the two hauls is on this sites" previous posts, which I can' t locate at this point. Advise you to research further.

Yes sir the 23 is a 20 degree hull with the 25 at 25.5 degrees. I’m the kind of person that will find every bit of information before I get started so I have a long road ahead of me. I did start a few months ago and have read about Navatek studying them. Hope to get in touch with him soon.

[cdavisdb]

Here is an idea for a cc.. Jackshaft a diesel to an outdrive, move the engine as far forward as possible. Navetek did something similar. That might get the horizontal cg right. The 25s ride is so good that a cc with an extremely far forward console would work, comfortwise. Leave lots of fishing room as well.

[Glaucus485]

Xcomunic8d,

Thank You! You are correct. There isn’t quite as much space from the existing plywood subfloor to the top of the keel stringer as I thought from when I was looking around the other night. I would agree that a raised keel stringer for a shelf would be in order across the top of your the lower stringers. I don’t doubt that an I/O would produce the absolute best ride.

[Glaucus485]

Originally Posted by cdavisdb

Here is an idea for a cc.. Jackshaft a diesel to an outdrive, move the engine as far forward as possible. Navetek did something similar. That might get the horizontal cg right. The 25s ride is so good that a cc with an extremely far forward console would work, comfortwise. Leave lots of fishing room as well.

Thank You for the input Sir! I like the idea of the console being slightly more forward than maybe typical but I don’t plan on sticking with an outdrive. I did ride in a Custom 31 Contender Openfish with a single Yanmar and straight shaft in about 1999 and absolutely loved that boat!

[Glaucus485]

Does anyone know of someone in Florida with a Seafari 25? Curious to chat with them and maybe take a ride in one for my research.

[Xcomunic8d]

I don’t know of anybody but I’d listen real closely to the guys here. Many of them spent time discussing the design with the designer personally. Terry, nobones, flexpat, and I’m sure I’m leaving guys out.

Also navatek or bigfluke? did serious research on this hull for USN.

Guys who owned this boat
Strick, Cdavisb, blue heron and 6stretch2, ?? Sorry if I’ve left anybody out…

Here’s some vids. This is how I did the same research you’re doing. The boat likes weight forward.

Note the ride on this video
https://www.youtube.com/watch?v=ln3Y1A_RNCM

And note the ride in this one.
https://www.youtube.com/watch?v=6aR5yg-LfFI

I did all kinds of math jumping jacks and wound up moving cg back 12” no matter what on calculator. Flexpat says you can get to 6” but would need serious freshwater up front. 90 gallons? And a single outboard. Even that is just too much in my opinion- cg compromise and weight add for too little return.

I’m no marine engineer but there are guys here who are.

[Glaucus485]

Found this rendering done from here on this site. Surely it’s a rough draft but seems like it can be done. I don’t think any hull will ride “better” with an outboard but considering I don’t think I’m capable of going the I/O route if I was honest, I would be happy with the outboard route.