25 seafari questions

[stumpie2]

as i mentioned before, im in the process of repowering my 25 seafari with a bracket and an outboard.... i have a question that has me scratching my head... per the specs section here on csc the 25 seafari only weighs 3000 lbs without the engine (dry)... something about that doesnt seem right. compared to a 24 albe at approx.5000 lbs. am i missing something or is this correct... maybe i should tow it to the salvage yard a use there scales to get an approx. weight?

[htillman]

I weighed my 23 to check to the weight during and after the rebuild. It was fine and the weight was fairly per the specs.

[3rdday]

To the scales, so that yo have a KNOWING!
If you are all stock and significanlty over the specs, start looking for water in stringers, decks, transom and foam. If none found there, There is a chance the polyester resin which is what was used back then and the only technology avaible, may have absorbed water. no big deal unless you get osmotic blistering, but I would not expect that unnless the boat is kept in the water.

[stumpie2]

no water logged structure in the boat... new stringers and bulkheads in '06 and trailer and dry stored since... the 3000 lbs. just seemed a little light especially since many sc owners are running high horsepower engine(s) compared to the light weight of the boats... a buddy of mine runs a '03 25' trophy, listed 4250lbs. with a 225 opti on a bracket and ive seen 43mph gps at 5500rpm. so if the 25 seafari is only 3000 it ought to fly with a 250 merc efi... i understand the deadrise of the hull may factor into the equation, but i cant see where i will need anymore hp unless im overlooking something... any comments?

[Fr. Frank]

I just looked at the BUC website and the 2003 2509 WA Trophy OB model is listed as 4400 lbs net weight. The net weight of a boat is based upon buoyancy, and is the weight of the hull, plus power, fuel, persons & gear. It is also called displacement.

For example, my 20' Seafari has a listed hull weight of 1800 lbs. My motor weighs 375 lbs, I carry 28 gallons fuel, and I have a max capacity of 9 persons, or 1455 lbs persons and gear. If we go with the max of 1455, the equation looks like this:
Hull - 1800 lbs
Fuel - 168 lbs
Motor - 375 lbs
Persons/gear- 1455 lbs
Net Weight or Displacement - 3798 lbs

For your 25' Seafari: Hull - 3000 lbs, 105 g. Fuel - 630 lbs, 7.4 L sterndrive(1982 weight w/ TRS) - 1244 lbs, Max capacity persons & gear - 1619 lbs = 6493 lbs net weight.

So an "apples to apples" comparison using your examples is:
2509 Bayliner Trophy = 4400 lbs net weight or displacement
25' SeaCraft Seafari = 6493 lbs net weight or displacement

[Ryank]

We salvaged and scrapped a 25 fly bridge that weighed 2800 w/out engine or fuel, it took the D6 dozer approx 20 seconds to make it look like a flat pancake that couldn't have weighed more then 500lbs lol. It was amazing to watch.

[seafari25]

I just looked at the BUC website and the 2003 2509 WA Trophy OB model is listed as 4400 lbs net weight. The net weight of a boat is based upon buoyancy, and is the weight of the hull, plus power, fuel, persons & gear. It is also called displacement.

For example, my 20' Seafari has a listed hull weight of 1800 lbs. My motor weighs 375 lbs, I carry 28 gallons fuel, and I have a max capacity of 9 persons, or 1455 lbs persons and gear. If we go with the max of 1455, the equation looks like this:
Hull - 1800 lbs
Fuel - 168 lbs
Motor - 375 lbs
Persons/gear- 1455 lbs
Net Weight or Displacement - 3798 lbs

For your 25' Seafari: Hull - 3000 lbs, 105 g. Fuel - 630 lbs, 7.4 L sterndrive(1982 weight w/ TRS) - 1244 lbs, Max capacity persons & gear - 1619 lbs = 6493 lbs net weight.

So an "apples to apples" comparison using your examples is:
2509 Bayliner Trophy = 4400 lbs net weight or displacement
25' SeaCraft Seafari = 6493 lbs net weight or displacement

Fr. Frank

In no way am I opposing what you are saying. In fact, my signature should read "wisdom is learning from Fr. Frank" by now but this topic is of particular interest to me. Not just because we're talking about my favorite 25' boat but also because I'm in the scale business.

On the Railroad, we refer to net weight as the weight of product in a rail car not including the light weight. The 2 added toghther would equal the gross weight.

In my mind, displacement should be the gross weight.

Are the terms different on the water

Brandon

BTW Nuthinfancy I`ve never had the opportunity to check the dry weight of ours but I think Fr. Frank`s right on at around 6 to 7000 lbs displacement according to the guy that stores our boat for the winter (although he hasn`t actually weighed it). I guess he just has an idea compared to other boats he stores.

[stumpie2]

I TOTALLY RESPECT FR. FRANKS INSIGHT BUT I WISH THERE WAS SOMETHING TO COMPARE APPLES AND APPLES TO.. SUCH AS ANOTHER 25' SC TO COMPARE TO OR A BOAT OF SIMILIAR DESIGN. IE SEABIRD, ANACAPRI, ALBE... O I FORGOT THERES NUTHIN LIKE A SEACRAFT... BECAUSE IM TRYING TO AVIOD WEIGHT ISSUES AND REALLY DONT WANT TWINS= NEED MORE FUEL AND MAINT. AND THE BIG 4 STROKES ARE SO LAZY AND HEAVY

[Fr. Frank]

In my mind, displacement should be the gross weight.
Are the terms different on the water
Brandon

I don't know how anything else is weighed. The USCG lists the net weight of a vessel as the weight of the volume of water the vessel displaces as loaded. It is mathematically the same as the vessel's displacement. But as water density can vary, the net weight can change, whereas the calculated displacement remains the same. Displacement is always calculated against fresh water at 59* Fahrenheit. (I don't know why it's calculated that way, but it's the same temperature used as a base when calculating "density altitude" in flying.

At any rate, the net weight of a vessel is the weight of the volume of water it displaces at current loading at rest in current waters. Manufacturers who use net weight for statistical purposes assume maximum loading in fresh water at 59*.

Just make things confusing, the volume of water displaced must actually weigh LESS than the actual weight of the vessel. The difference in weight is called "buoyancy"

Manufacturers generally calculate a vessel's "dry weight". This is the weight of the hull and structural fixtures when dry. It does NOT include the weight of a power-plant, fuel, cushions, seats (unless molded as part of the liner or cap), etcetera, or any optional equipment.

[Blue_Heron]

nuthinfancy,
I think Fr. Frank's numbers are pretty close for the 25 seafari. 6000-6500lb give or take sounds about right with power, fuel, crew, and gear. I thought about dragging mine to a scale, but I haven't done that yet. Don't know the trailer weight and don't want to launch it in its current condition just to weigh the trailer.

But... Weight is one thing, weight distribution is another.

From what I've read on this site, and from communication with other owners of 25 seafaris, I think you should look long and hard at your decision to go with a bracket and outboard. The 25 seafari, in its original configuration, has a center of gravity that is high, and pretty far aft. That's why some seafari 25 owners have found ballast under the cabin floor, placed there by previous owners. It's also part of the reason Carl Moesly designed his patented automatic ballast tank system for the 25. If you replace the I/O with a bracketted outboard, the CG will move even higher and further aft.

As an example, CSC member Bigfluke owns three of these boats. One has been converted to a center console, but still has a big block I/O. Bigfluke is a marine architect, and his company in Hawaii has developed an unmanned vessel for the DOD based on the 25 Seafari hull. He says the 25 seafari is the most seakindly hull of its size he's ever run. Of the three 25s he's got, he has said the CC has the best ride because the conversion moved the center of gravity forward and down. It would be worth your time to read through his posts and maybe contact him to discuss the ideal weight distribution for this hull.

Sorry if I sound like a know it all. After all, you've owned and run your 25 for years, and I haven't even had mine in the water. But based on what I've read, I plan to replace the 270 HP carbed 350 I/O with a 300-350hp MPI I/O package motor and keep all added weight as low and as far forward as possible.

Whatever you decide to do, good luck with the repower.

Dave