25 seafari questions
 

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?

Re: 25 seafari questions
 

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.

Re: 25 seafari questions
 

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.

Re: 25 seafari questions
 

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?

Re: 25 seafari questions - weight calculations
 

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

Re: 25 seafari questions - weight calculations
 

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.

Re: 25 seafari questions - weight calculations
 

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 :D

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.

Re: 25 seafari questions - weight calculations
 

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

Re: 25 seafari questions - weight calculations
 

Sounds light to me also, I thought my 23 Sceptre was 3540 dry. Check a newer 25 CC and see what it lists at ??

Re: 25 seafari questions - weight calculations
 

THE NEW SEACRAFT 23 CC HULL IS APPROX. 4200 LBS AND THE 26 CC HULL IS APPROX IS 4600 LBS. I THINK THEY WEIGHED THESE THINGS DIFFRENT BACK IN THE DAY... MAYBE NO LINER OR CAP JUST THE EMPTY HULL...

Re: 25 seafari questions - weight calculations
 

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" :D

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.

Re: 25 seafari questions - weight calculations
 

If that was a 23T which I think it is - they are really 25, the cheater boats for the Kingfish guys like a Contender 23T

Re: 25 seafari questions - weight calculations
 

Found a 1965 Formula catalog that showed the 233 at 4200 lb. That was the original mold and they put a whole lot of glass in it. I have seen other quotes at 4100 lb for later years. That is dry with engine. My old Seabird 24 was 3900 lb with a 350 outdrive. Subtract the engine and around 3000 lb seems reasonable for those boats. The 25 has more weight up high than the Seabird and is 1.4 ft longer. My 25 seems more solid than the Seabird and some heavier overall, but that's just my impression, have not weighed it. Still, 3000 doesn't seem too far off.

Connor

Re: 25 seafari questions
 

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

Re: 25 seafari questions
 

Just to reinforce the center of gravity issue. I just got a 1972 25 seafari/ 5.7 volvo duoprop after owning a 24 seabird, with the same power, for many years. I haven't had it out yet in rolly weather, but just riding around the bay, its very obvious that the center of gravity is much higher than the seabird. The seafari is also much more "tippy" while in motion, its noticeable. At rest, the flat hull sections near the stern seem to damp out the roll pretty quick, but that's just based on a few boat wakes, not a good test. Overall, I'm with Blue Heron, raising the CIG further with an outboard doesn't sound like a good idea.

Interesting comparison: At cruise,3300 rpm, the seabird with stainless props is only about .6 knot faster than the seafari with aluminum props.

Connor

Re: 25 seafari questions - weight calculations
 

That makes sense to me, it was just the word net being used for an entire weight that conused me. I`ve read that the same boat will float higher in salt water than in fresh. That`s interesting...I`d like to test that theory one day.


I`m in agreement with the recomendations of Dave and Connor but I`m pretty sure nuthinfancy is set on a bracket and outboard. I believe it can be done if done right. Hopefully Strick will chime in as he`s really done his homework on this topic.

Re: 25 seafari questions - weight calculations
 

yeah shes gettin the outboard and bracket.. im just getting my numbers right and weight distribution right.. measure twice and cut once type deal.. im already knee deep into this and imma go the whole nine yards. my original idea was move the cabin door to the port side (toilet removed 2yrs ago due to coast guard issues with no holding tank) and go center steer with a carolina style helm pod,express type deal, and cooler/bench seats along the sides. but vision might be an issue with the windshield seam in the center. if the sceptre windshield will fit that might solve that.. getting rid of the two 50 gal tank and putting single large one further forward... just playing with ideas

Re: 25 seafari questions - weight calculations
 

My Anacapri Holiday 25 (similar to the Seafari 25 style) with a 350 cubic inch V8 outdrive has a net dry weight of 4000 lbs and the Holiday V-250 (same boat but set for outboard power) is 3700 lbs without power and dry. And these boats have a very thick bottom layup so they compare favorably with the 25 Seafari.

Re: 25 seafari questions - weight calculations
 

i had a 1999 proline 251wa it had a dry weight of 4200lbs and it was all of that outfitted with motor and fuel plus extras i figured it about 7000lbs

Re: 25 seafari questions - weight calculations
 

castalot, what type of power did you have behind that 251 proline. theres a guy at the marina that i worked and kept the boat at that had one with hard top and curtains powered by a SINGLE 250 evinrude ficht. that has flown past me like i was tied to a stump. i think i can get away with single outboard power and still scoot along pretty well.

Re: 25 seafari questions - weight calculations
 

Here's what I figure on speed for your 25' Seafari, based upon your hull shape and bottom paint, with the right prop, + or - 10%. These are approximate results I got with a 1973 25' Wellcraft Nova II conversion from twin 165 hp sterndrives to single outboard on a Gil bracket to twin outboards on Gil Brackets. The boat belonged to the marina where I worked, and we changed it around quite a bit. It had K-planes already installed. All the results below were without using the planes.

We tried a single 235 Evinrude 1st. That was a pig. Then we tried a single 250 hp V8 Evinrude. We blew the powerhead in under 30 hours. Then we mounted the 275 3.4L Mercury. We ran that for a couple of months, then we switched to twins. Of the above, only the V8 Evinrude was a new motor. The BB Mercs were rebuilds from the Marine Patrol.

Original twin 165 hp Mercruisers cruised at 28-30 mph, 4-5 seconds to plane, WOT around 41-42 mph.
Single 235 hp Evinrude V6 cruised at 23-25 mph, 8-10 seconds to plane, WOT around 28-30 mph.
Single 250 hp Evinrude V8 cruised at 29-30 mph, 7-8 seconds to plane, WOT around 34-35 mph.
Single 275 hp Mercury BB V6 cruised around 29-30 mph, 5 seconds to plane, WOT around 38-39 mph.
Twin 275 hp Mercury BB V6 cruised around 34-35 mph, 3-4 seconds to plane, WOT around 46-48 mph.

Either the single 250 hp V8 or the 275 hp V6 had acceptable performance. Note that even twin 275 hp could not get the boat above 50 mph. I remember the single Mercury 275 used less fuel (23 gph) at near WOT (5200 rpms than the Evinrude 250 at cruise rpms of 4300 (24 gph).

While I suspect you'll use less fuel than the above, performance should be comparable.

Your major hurdle will be managing your CG.

Re: 25 seafari questions - weight calculations
 

fr.frank thank you, for the good piece of info. i dont need to race anyone. i just want more cockpit space and efficiency(sp). while "freshing up" the boat at the same time

Re: 25 seafari questions - weight calculations
 

nuthinfancy

it had a 260hp mercruser fuel injected fwc 350ci with the bravo 3 drive a great combo top speed was mid to upper 40's and it sipped fuel between 25-28 knots and rode sweet plus she carried a 1000lbs of fuel 175gals!!!!

you should be fine with a single at 250+hp i'm not suprised you were passed trimmed out the 251 will fly but trim it in a little and they cut the seas like a knife i was very happy with it just never had time for it so i went back to trailering and bought my seacraft!!!
good luck and keep us posted
matt