hydro shield?
 

my son bought a 25 seafari this summer and it is a beast but if you make even a slight turn it leans real bad to the side you are turning. would a hydro shield help with this? it has a 225 etec on it. thanks

Not sure. Think about just getting used to it. The hull is so sharp that it will have a strong tendency to lean in turns. There are some considerable advantages to that tendency. For sure, in the I/0 versions (mine), the hull never feels unstable. In a very tight turn, it will lay over so far that it can spin, but never in a way that feels out of control. Its a very odd feeling for the boat to be doing something that usually means it is out of control (spinning) and still be in perfect control. I always warn new passengers about the lean, but hardly notice it myself. Lean or not, the boat always feels solid, capable of running through anything the weather can throw at it.

The boat likes weight forward. I wonder if something like a hydo shield would provide move lift in the stern and positively affect handling in ways other than lean?

Has trim tabs ?

Not sure a hydro shield would do much for the leaning. I would suggest playing with the trim tabs (if he has them) and the engine trim. May take a bit of time but he will find the best ride

yes it has trim tabs and you have to use them every few seconds and that gets old running 70 miles to the canyon. I am fine with the way it leans in a big turn but I think it should be able to run in a straight line without falling over on its side. we love the boat we just want to get this figured out. I am not saying its not the operator but I have ran boats offshore for 30 years and this is a first for me.

Member Blue Heron made some custom tabs for his sled. They followed the shape of the outer and middle panels at the transom. I`ve been on board and she tracks beautifully.

I'm wondering if there is something about your boat that is making it worse than normal. Mine tracks fabulous, leans a bit from side to side when passengers move around, easily corrected with trim tabs. The boats sensitivity can be turned to great advantage. Just a tweek of the wheel one way or the other and you can keep the keel coming down perpendicular to the water surface, much smoother ride that way. Driving that way gets automatic after a while. Sounds like your boat is doing something different. What power? How much weight do you normally carry in the bow? Anything else different from a 5.7 v8/I/O, 100 gallons fuel?

I get what you're experiencing and it's annoying just thinking about it.
I test drove a hydrosport that did the same thing and I agree..... it gets old.

Is the engine mounted too deep ? Maybe not the issue.
What RPM's you getting at WOT ? Too much prop ?
Does it still flop over with the tabs down about 1/2 - 3/4 evenly ?

If that's the boat I'm thinking......I believe they rebuilt the transom ?
Not sure but I do remember the picture looking different in that area.

Hummm......we need to figure this out.
I'd suggest calling some boat engineering / boat racing contacts for ideas.

I'm not sure if the 25 Seafaris run as true with outboard(s) as they do with cast iron in their bellies. Conner and Dave (Blue Heron) both are running sterndrives as originally designed. I had a friend (Jack Roddy) with twin Volvo "pushrod" 165's in it and he removed them and put a pair of 200 Hp Merc 2-S on an Armstrong bracket. It would yodel, but, as you say would just roll over on it's side if someone got up to get a beer out of the cooler. He had tabs but that seemed to have no reaction then an "over" reaction. I had another friend (Dennis Hill) who had a single 225 OMC Sea-bracket motor on it. His seemed to be more stable to me, because the motor was closer to the transom and ran deeper in the water than the twins. A 25' Hydrasport I was in acted similarly to the twin Merc 25 SeaFari - Trim out nicely and pat tab, pat tab, pat tab and wham it would lay over on it's side. Spookey. Conner and Dave have it down, but they have Chevrolet "Ballast".

it has a 225hp etec on a notched transom and it has 120 gal fuel tank right up the middle and a 40 gal fuel tank where the io would go. on a tuna run we will put about 300lbs of ice in the cuddy which makes it slice the seas even better but it still wants to lay over at the slightest turn. if you wanted to would you be able to use auto pilot on nice days? we don't have one but I could not see it working on this boat. I know you guys say this is a drivers boat and I do know what that means. I have had boats you have had to work at in rough seas but you have to do that with this one in calm seas. I hope it does not sound like I am bitching to much I just want to get this right for my son.

Terry you hit the nail on the head on both accounts. the problem with some one moving around does not bother me I get it is a deep v boat and you are going to have that. the problem you described with the hydrosport is what drives me crazy.

I act like a goof on here most the time, mess'in with Minh and his gay sports cars but actually I'm old and have a lot of scar tissue running these boats. They do great the way they were originally designed, but when you start "improving them" by changing things around all bets are off on the preformance category. Carl Moesly had it figured out.
I always wondered if those big long Kiekaefer K-planes and a 4 blade stern lifting
prop would help on the outboard 25's - then maybe 400# of concrete in the anchor locker. We do know how to spend your money here. She'll ride better on the way home if you fill the cabin walkway with swordfish. Git to work and circle back with some data we can use.

As Terry E. mentioned, Connor has his 25 dialed in very well with the original I/O configuration and it seems to handle pretty well. You might try using Capt. Terry's CG calculation method to calculate how much the lateral CG has been shifted by the change from I/O to OB configuration. You could then use the same procedure to calculate how much ballast you'd have to add up in the bow to get the CG back to it's design location. You could also use that process to figure out CG location with the 300 lbs of ice in the cuddy and see how that compares to the design CG location.

Carl Moesly designed this boat to have a ballast tank up in the bow using a rubber bladder tank (so it could be filled and emptied quickly w/o needing a vent hose), similar to what he used in his race boats, but he sold the company to Potter before he ever built one, and Potter evidently didn't understand the ballast tank, so left it out. So maybe a rubber bladder ballast tank up in the bow would help the handling.

I wonder if your problem is related to the vertical CG location. As Terry E. mentioned, that lump of Chevy iron down low in the bilge in the original design probably makes the boat more stable in roll than it would be with an outboard powerhead mounted up at 25-30" above the keel. If a marinized SB Chevy weighs ~900 lbs with manifolds & risers, at about 5.9 lbs/gal for gasoline, you'd need something like a 150 gallon gas tank down where the engine was to match the original configuration!

If we're spending your $$$$$ then I say get SesKeeper��

https://www.seakeeper.com/

Now we're talking! ;)

Hmmm. This sounds like a vertical CG issue, probably related to using an outboard. My I/O doesn't act like that at all. The outboard will have a high vertical CG. The 25 Seafari has a fair amount of cabin weight up high anyway. The 25 Hydosport is the same thing, relative lot of cabin and hull weight high plus a very deep, slab sided deepV.

You would think that a full load of ice and fuel would pretty much counter that problem. Does the boat act better or worse when its light? Some CG calculation(see above) seems like a good idea.

How high off the deck is all that ice?? Could that be contributing to the problem?

You might want to work the motor trim, but it sounds like something may be off, not sure what though. Mine definitely leans on tight turns but not on adjusting turns.

Its funny when i go and drive someone elses boat it feels like it takes forever to turn because they dont have the lean. You get used to what you helm.

Capt Nate, yours is a bracketed outboard with a fairly heavy hard top, much higer CG than mine, yet it doesn't do what bad habit is describing. What's the difference? I was thinking vertical CG, but maybe its something else.

Just a thought. The 25, being so sharp, is quite sensitive to the amount of weight you put in it. My mpg and speed/rpms at 7 lbs vacumn go way down when I'm loaded heavy vs a light load. Maybe it can be sensitive to weight in other ways. Sounds like your canyon runs are a heavy load. Could this be related to the handling issue? Again, does it do it just as bad with a light load?

Mine also has 2, 45 gallon tanks midship that stay full.

I played around with my motor trim today and it really changes the way it turns along with efficiency. Had it trimmed up higher than typical and seemed to free up the wheel more and level out the turns. I'll fiddle with it more when the winds die down.

Does it lean to both sides with same ferocity, or primarily to one side? Does it lean with with tabs neutral/up and even? are tabs perfectly aligned? it takes but a smidgen of tab to change the running attitude of your hull. How high is the motor? vertical cg and lack of rudder...

is motor perfectly centered?
Does drive leg have torque tab? slightest bit off center can cause the bow to lean...

Fuel tanks flat bottom or v? is fuel sloshing side to side, a'la the mitchman effect...

Finally, your single motor is very light for a 25. Considering most folks are putting too much weight aft on their repowers, this is going to sound odd, but I think you may actually be running a little light on the stern. Some of these rigs were dressed with a pair of chevy 250 inlines. The chevy ballast concerns are quite valid, me thinks...

Might consider setting 5 or 600lbs of sandbags centered in front of the motor and see if see runs a little more true to help define the problem.

my son and I took it striper fishing yesterday. with the tabs all the way down it still seems like the bow rides high. I had my son witch is 270lbs get in the cuddy. that did help the ride some but I feel like it needs more. we were full of fuel 120gal in the center and 40gal in the back. do you guys with the safaris ride bow high at all?

Mine likes weight in the bow,smoother slightly faster ride, but I wouldn't say it rides bow high. Normally rides flatter than most boats I've owned. usually don't use significant tabs. I tend to use more tabs late in a long trip when the water supply stored far forward is exhausted. Really notice a heavy passenger moving forward when the bow is light. When I'm loaded heavy, I've got somewhere around 300 lbs aft of the transum, between kicker, jerry cans of fuel, platform and stored dive gear plus about 200 lbs of water weight and grocerys as far forward as I can get them. . Light load most of that is gone, but there is still 200 lbs aft of the transum. That really should not be all that different from the weight distribution with full fuel of your rig. I'm thinking there is some connection between your boats tendency to lean all the time and the bow up thing. Not sure what that could be, but neither match my experiance. Motor trim, motor height, lifting prop, trim tab, something weird? How slow will yours stay on a plain? It should go down to around 13 mph, tabs and trim down.

thanks for the reply. the bow rides higher on this boat than any I owned besides my 34 hatteras. the boat was able to make small turns without falling over to bad with my son up front so we are thinking about putting 400lbs up front, we just hate putting so much weight on the boat. even with the bow a little higher than I think it should be we walked away from a 25 grady white in 2 to 3 foot chop the other day.

The ride of the 25, going fast in slop is just hard to believe. A Grady trying to keep up would be way out of its class.

There is something not right about how your boat is set up. I know what you mean about smaller Hatterases tendency to point their bow at the sky. Your 25 definitely should not do that, ever, ten times more so when it loaded like you described. If something was forcing the bow too high, you would be running on a small portion of a very sharp hull, far back toward the stern. That would make it unstable and might well require constant attention to the tabs. it would probably also mean that the hull would fall off a plane at a relatively high speed, something like 17 knots. Can you post some pics of the stern of the boat, showing exactly how the motor is mounted, normal engine trim for running, prop used, tab position, etc? Pics of the boat running?

The boat should track like it is on rails, even when it is pretty rough. Does it?

Troll?

I will take some pictures within the next few days and the next time we take it fishing I will try to take a video of it running. in anything but glass conditions we run with the tabs all the way down. I would not say the boat ran on rails but when we hit a big wave and I am sure it is going to slam it just sits back down nice and soft.

gofast, I am not a troll if that is what you are saying. we found this boat this summer because some one on c s c posted that one was for sale on ct craigs list.

Do you have previous owners contact info?

Original question was about the HydroShield. No, this amazing device will not help the tendency of the 25 to want to bank like a fighter jet in the slightest turn. But yours sounds like it's gone from being nimble to being downright twitchy. One is fun, the other gives you a tired set of Kegel and gluteus muscles.

I think several people here are on the right track with addressing the CG, both vertically and longitudinally. If you run with just a couple of degrees of down tabs on both sides it will help tremendously. Even when the hull leans/banks in a turn, it will quickly return to upright when the vessel is once again going straight. How many degrees of tabs you'll need to run you'll have to figure out on your own.

The only 25' I've ever worked on and had to block up was a twin stern-drive model, and with full fuel it had a longitudinal balance point about a foot behind the cabin aft bulkhead. It did have ballast bars below the cabin floor. We ended up putting two keel blocks under here plus two Brownell stands.

By contrast, my current '71 Seafari 20' with 140hp sterndrive balances fore and aft just 8' forward of the transom with no fuel. (I've never blocked it with fuel in the tank).

thanks frank. it seems like it rides best with tabs all the way down. do you know how much ballast was in the one you worked on?

I think there is something in the OP symptomatic complaint that points to a possible issue that has been overlooked. The symptom of tab, tab... Fallover is a classic symptom of non- baffled fuel tanks. Is the main tank new? What about the 40 gal in the stern? Are the symptoms just as pronounced when the tanks are full? Just something to consider....

I think Gillie and Ken nailed it with the fuel sloshing/tank baffle comments! 120 gallons is a BIG tank that should have several baffles in it.

When a boat is already marginally stable in the roll axis, an un-baffled tank would tend to make it highly unstable because a little bit of roll shifts fuel weight in that direction, causing more weight shift which causes more roll, etc. A total of 160 gallons of fuel that's free to go where ever it wants to is almost a half a ton of mass that you have absolutely no control over! A 400 lb cooler in the cabin is a nit by comparison! Imagine having a roly poly 500 lb passenger free to roll around on the deck that immediately rolls to the low side as soon as you start a turn! I'm surprised you're even able to control the boat at all! Kinda like trying to balance an anvil on a broomstick!

Did you notice any difference in handling between when the tanks were completely full and maybe after you burned off ~ 1/4 tank? The mass can't move around when tanks are completely full, so I could see you starting off the day with the boat handling fine and then gradually turning in to a nightmare!

Non baffled tanks would explain a lot, but not the bow up business. More than one issue?

I bet with an empty rear tank and 30 gallons in the main it's a different boat. I would do lots of experimentation starting with fuel weight.

This is the boat

Good looking boat

Is that ruler in inches? Is that the normal trim angle that you run at? Can you post a pic of how the prop direction lines up with the keel(at right angles to the hul)? So we can see if it is trimmed in or out.

If its inches, and comparing to my I/O drive (a lousy comparison) it looks to be trimmed too far out, which would make the bow ride high.

I am not sure if it is in inches, the boat is kept at a friends house and I just grabed a t square he had. I will try to get better pictures this weekend starting with the motor all the way down. as far as the fuel tank the tag on the big tank says 2004. I think the smaller one is the same but I will have to check. the last time we took it out both tanks were full and it might of been a little better or I might just be getting used to it. my son is 25 years old and is a commercial diver and has been around boats all his life and he wont even run his own boat. lol

kmoose, on sea trial back tank was empty and the big tank had about 15 gal in it. it was flat calm and it ran great.