SE Hydrofoil

[Dogsluvtrux]

I have a 1998 Searay 180br with 3.0 mercruiser...curious if anyone has experience with a hydrofoil. Last year I was very unhappy with the holeshot, so
I replace the prop its a four blade, made a significant improvement! I then added an aftermarket swim platform and need a bit more help getting on plane and it porpoises quite a bite now, not surprising since I added the extra weight off the back. I looked at nauticus smart tabs, seems like a great option, but due to mounting brackets for the platform, the only place I have left to mount them would involve cutting tabs off the trailer and re-welding, and the measurements indicate I would still have clearance issues with the tabs and the ratchet straps holding the back of boat.

Would the hydrofoil help with the porpoising? Any reviews from someone with a foil?

 

[alldodge]

I have a 1998 Searay 180br with 3.0 mercruiser...curious if anyone has experience with a hydrofoil. Last year I was very unhappy with the holeshot, so
I replace the prop its a four blade, made a significant improvement! I then added an aftermarket swim platform and need a bit more help getting on plane and it porpoises quite a bite now, not surprising since I added the extra weight off the back. I looked at nauticus smart tabs, seems like a great option, but due to mounting brackets for the platform, the only place I have left to mount them would involve cutting tabs off the trailer and re-welding, and the measurements indicate I would still have clearance issues with the tabs and the ratchet straps holding the back of boat.

Would the hydrofoil help with the porpoising? Any reviews from someone with a foil?

IMO, first get rid of the four blade and put the three back on. The four blade is great for picking the stern up out of the water more, but then you get porpoising. To stop it you need the stern back in the water and/or more weight forward. While I'm a fan of the stingray (not the flimsy ones) hydrofoil I have one on my 23 footer, I don't see it helping your problem. You have to much weight on the stern from the swim platform being added. The hydrofoil lifts the stern a bit but, it also creates drag, and you don't need anymore drag. You need more HP or less weight., so you need to figure out what gets left at the dock.

:ballchain: or :very_drunk: or rug rats

 

[64osby]

One of my old boats had a fin (Merc 500 on a 16'er) . The boat still porpoised with the fin. The only cure that worked for my boat was adding 2 -25lb sand bags up front. Not a great fix IMO.

I would look at tabs for you hull. Everyone that installs them gives them great reviews from what I read.

 

[rallyart]

A hydrofoil sill get you up out of the hole much vaster and also let you control speed more when not on plane. It won't help porpoising. Trim the engine in (down) and keep weight forward. Tabs will help with porpoising.
Try moving the battery forward along with any other items you store on the boat. Another alternative is to not run at wide open throttle as normally porpoising will only happen near top speed.

 

[JimS123]

The boat was designed to run as built. That means with the battery, gas tank, etc. where it was. You changed the design by adding weight where it wasn't supposed to go. Adding weight forward might alter the problem in the other direction, but your overall performance will be worse.

Keep the 4-blade, add a DoelFin (not an SE, Stingray or whale tail), trim the outdrive in all the way, throttle back and just live with your inability to go real fast. In the end you'll get better gas mileage so it won't be a total loss....

 

[thumpar]

There are not many bandaids you can put on it. A 3.0 is kind of small for a 18'. I am not a fan of the fins.

 

[smokeonthewater]

Smart tabs Smart tabs Smart tabs

FIND A WAY to put the smart tabs on..... VERY VERY VERY much WORTH IT...

the fin, not so much.... KEEP the 4 blade prop, you certainly don't have too much stern lift.... I have a stern heavy cruiser with twin V8 engines... I haven't got to 4 blade props on it yet but have on many other stern heavy boats and they ALWAYS help... My boat is prone to porpoising at higher speeds (40-48mph) when I trim the engines up for speed and my trim tabs absolutely STOP it right NOW..... Mine are helm adjustable but I have often thought I would prefer automatic tabs if they made em for a boat this big.