SE sport 300 hydrofoil

[BigE]

Looking for an SE Sport 300 Hydrofoil

Anyone got one they want to part with ?


BigE

[shakey55]

I have the 400. Very happy with performance and NO DRILLING


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[gazza2006au]

I have the Ozplate that came on my engine i took it off to fix in a test drum and found my boat doesn't even need a hydrofoil

BigE how come your fitting one?

[BigE]

Gazza
borrowed one from a mate and it a good amount of improvement ( and i didn't think the yalta's performance was poor to start with)

had a 160km run in about 15's with some chop (scarby to 12mile to wide of the cape to tanga and back to scarby) fuel burn went from 2km to litre to 2.2 km to the litre engine had a bit more useable trim at cruise and the boat just felt "higher " in the water seemed to add more lift all all planing speeds.

in short I liked it on this hull, I know they dont work on all hulls and there not some sort of black magic but 10% better fuel burn at 40kph is worthwhile improvement , thought someone might have a used one they didnt want ($$$ for Xmas)

BigE

[gazza2006au]

Big do u think the sifference could have been the conditions on the day?

[Andy56]

Gazza
borrowed one from a mate and it a good amount of improvement ( and i didn't think the yalta's performance was poor to start with)

had a 160km run in about 15's with some chop (scarby to 12mile to wide of the cape to tanga and back to scarby) fuel burn went from 2km to litre to 2.2 km to the litre engine had a bit more useable trim at cruise and the boat just felt "higher " in the water seemed to add more lift all all planing speeds.

in short I liked it on this hull, I know they dont work on all hulls and there not some sort of black magic but 10% better fuel burn at 40kph is worthwhile improvement , thought someone might have a used one they didnt want ($$$ for Xmas)

BigE

Its an interesting topic on its own. I always suspect statements where the foil seems to "fix" underlying issues. Keeping the boat on the plane will improve your consumption figures. So working backwards, why is your boat not keeping on the plane without a foil? What are the factors at play?

Weight balance of boat hull, power available, depth of motor ( is the anitventilation plate too high or too low), prop selection, is the center of balance too far back with the weight of the outboard, is the mptor trimmed in or out properly?

I am not totally dismissing the foil, but it does seem odd that a foil can overcome all the other issues without any draw backs.
It is logical to me that on a flat sea, it would work great in a straight line.
Its also logical that it can get the hull on "plane" at a lower speed. But at higher speeds, 40km/hr, it should be out of the water, so no effect. So whats going on here? If its still in the water, it would signal other issues.

However, what happens to boat behavior when its rough? To me its also logical that if your weight balance is wrong or the motor is set too low and the bow is flighty, it could become hard to handle with a foil in rough seas, you would end up traveling slower to remain on plane compared to a well sorted boat. It will feel like a rear steer car. If the logic is wrong , please correct me. I havent read anywhere a logical description about how a foil affects a boat ( apart from more lift at low speeds.) or which issues are fixed or exaggerated. Advertising hyperbole doesnt count. I can only use logic to try and understand the fundamental forces involved.

I am sure others will say it just works, get over it or stop trying to intellectualise it. Can't help the engineer in me . I need to know why before i accept something that appears to cut across logic.

I found this snipet on THT, "Of course they give lift, my point was that the hull should provide the lift rather than the engine--They work, but they address a problem that doesn't belong to the engine..."

[scottar]

Its an interesting topic on its own. I always suspect statements where the foil seems to "fix" underlying issues. Keeping the boat on the plane will improve your consumption figures. So working backwards, why is your boat not keeping on the plane without a foil? What are the factors at play?

Weight balance of boat hull, power available, depth of motor ( is the anitventilation plate too high or too low), prop selection, is the center of balance too far back with the weight of the outboard, is the mptor trimmed in or out properly?

I am not totally dismissing the foil, but it does seem odd that a foil can overcome all the other issues without any draw backs.
It is logical to me that on a flat sea, it would work great in a straight line.
Its also logical that it can get the hull on "plane" at a lower speed. But at higher speeds, 40km/hr, it should be out of the water, so no effect. So whats going on here? If its still in the water, it would signal other issues.

However, what happens to boat behavior when its rough? To me its also logical that if your weight balance is wrong or the motor is set too low and the bow is flighty, it could become hard to handle with a foil in rough seas, you would end up traveling slower to remain on plane compared to a well sorted boat. It will feel like a rear steer car. If the logic is wrong , please correct me. I havent read anywhere a logical description about how a foil affects a boat or why it fixes issues or which issues are fixed or exaggerated. Advertising hyperbole doesnt count. I can only use logic to try and understand the fundamental forces involved.

I am sure others will say it just works, get over it or stop trying to intellectualise it. Can't help the engineer in me . I need to know why before i accept something that appears to cut across logic.

I found this snipet on THT, "Of course they give life, my point was that the hull should provide the lift rather than the engine--They work, but they address a problem that doesn't belong to the engine..."

It all depends on your situation Andy. For the record - all of my boats have run foils for the last 25 years - and they were run without too.

Sure on some boats, a foil can "fix" a problem caused by an underlying issue that could have been otherwise rectified. Sometimes they do it at a fraction of the cost of a "real" fix. Do they do everything they say - yes but what they don't elaborate on is "under certain circumstances". They will pretty much make every boat plane quicker - hard to debate that and at some point in the rev range, they will save fuel (it's the "at some point in the rev range they neglect to mention) purely because due to the extra stern lift the hull is now planing and not pushing water - again - basic physics and pretty much impossible to refute.

On some boats, mine included, they get fitted simply because it allows the hull to simply do things it is physically incapable of doing without the foil - main one for me is plane at slower speeds for a smoother ride in rough conditions. This comes down to what sort of skipper you are and what you want your boat to be capable of doing. I have spent a fair bit of time offshore in some bloody horrible conditions in my younger days - going fast enough to allow the hull to generate sufficient lift when it's like this is simply not an option. A foil however is the cheapest and easiest way to make it possible. My 15'er would plane at 8 knots - not bow in the air pushing water - a clean flat plane. The results with the Victory are similar but at a higher speed. The fuel saving at minimum boat speed was significant in the Victory - it went from 0.6km/l @ 3000rpm with it's bow in the air to 1.2km/l (sometimes better) with a better ride as the hull was flat and using the bow as designed. Not fixing a "fault" - simply allowing the hull to do something it would under normal circumstances be unable to do.

My 11 foot tinnie is the same. If you can find an 11 footer that will plane at a slow speed without it's nose in the air with a 100kg plus in the rear corner - let me know. Fit a foil and set the trim - happy days.

The negative - in my personal experience - nothing that hasn't been caused by me and the way I have driven the boat. They generate a huge amount of lift - if you don't use your trim button, you can cause yourself grief for sure - heavy steering, ploughing and the subsequent broach are certainly all possibilities but if you learn to use it properly - just like any other "tool", the benefits far outweigh the negatives IMO. Small tinnies especially, do require some thought - I regularly adjust my trim pin depending on load and sea conditions - something I will bet that not a lot of the people who have experienced hairy moments have done. On a rig with power T&T it is obviously a lot easier.

Brands - I've run a few. Stingrays in the early days - even have a mate that ripped a mould and cast me one from alloy at one stage. I tried the SE Sport on the Victory but it created a huge amount of drag. I ended up with a Permatrim which still created some drag but a heap less. Took it off for a grand total of one trip when I fitted trim tabs - it went straight back on.

[blacklab]

That is well said Scottar.
Perhaps some do use them to correct bad set ups, or rigs they have bought under powered or set up badly,
Think of it as an aid, an improvement aid, look how trim tabs can be used, nothing wrong with the boats set up when wind and tide or weight distribution needs a tweek on trim tabs, Just adapting to the situation.
Scottar, a friend of mine a while back fitted one of those Tailfin hydrofoils, haven't had the opportunity to go out with him to feel the difference yet, but he claims it has completely transformed the performance of his boat, which I didn't think he had an issue in the first place. Cost him a couple of hundy and the way he's talking, he stated it's like a new boat, hole shot, steering, leveling up of the boat over the rough chop etc etc, I don't know whether or not you've seen one, but Geeez, there dead set UGLY ! I dont know whether I would subject an out board I own to bolting something that visually unappealing, BUT, My mate is raving about it. they have a facebook page etc, after looking at there sire, my opinion hasn't change, there still damn ugly.
An interesting read But........

[scottar]

That is well said Scottar.
Perhaps some do use them to correct bad set ups, or rigs they have bought under powered or set up badly,
Think of it as an aid, an improvement aid, look how trim tabs can be used, nothing wrong with the boats set up when wind and tide or weight distribution needs a tweek on trim tabs, Just adapting to the situation.
Scottar, a friend of mine a while back fitted one of those Tailfin hydrofoils, haven't had the opportunity to go out with him to feel the difference yet, but he claims it has completely transformed the performance of his boat, which I didn't think he had an issue in the first place. Cost him a couple of hundy and the way he's talking, he stated it's like a new boat, hole shot, steering, leveling up of the boat over the rough chop etc etc, I don't know whether or not you've seen one, but Geeez, there dead set UGLY ! I dont know whether I would subject an out board I own to bolting something that visually unappealing, BUT, My mate is raving about it. they have a facebook page etc, after looking at there sire, my opinion hasn't change, there still damn ugly.
An interesting read But........

Agree blacklab - ugly as a hatful of aholes. Best trialled on someone else's motor. Perhaps if old mates website didn't read like a dodgy copy of a Danoz Direct add

[Lovey80]

For me it fixed a problem that I created myself. After I got rid of the 25l tote tank in the little Webster and replaced it with a 65l built in tank in the ass of the boat it made it really ass heavy. The boat simply wouldn’t plane or ride like it did before and I was struggling to get any top end performance. After the foil however it was chalk and cheese. It launches onto the plane and I actually now have some prop testing to do because the current one spins out far too easily.

The one downside though is I have lost some trim up in the bow when it gets snotty. The boat wants to sit level in all trim settings. Being a creek boat that doesn’t happen very often.

[Paul071978]

I’ve had some average experiences with these things especially with beam and following seas. And yes I do know how to trim correctly. It made the boat very unpredictable. I wasn’t happy at all and removed it promptly and placed into the recycle bin

[scottar]

Just to elaborate a bit further on a couple of points you raised - yes, ideally over 40kph the foil will be out of the water - hull dependant. All hulls will have a minimum speed at which they generate sufficient lift to get their weight out of the water and planing. This speed will vary though based on weight given similar hull design. On a light alloy rig, it will obviously be less than on a heavy lay up glass rig . Weight distribution will play a part too but it doesn't matter how you distribute weight if your hull weighs substantially more - you will need more speed - unless you can somehow generate more lift.

"Travelling slower to remain on plane". Not at all - unless you want to. The trim control will control just how much lift the stern is generating on a good installation. If you want more boat speed, trim it up and give it the beans. Of course if it has gotten to the point that you want to slow down, remain in control instead of hanging on for dear life, not to mention avoid bashing the shit out of your boat and yourself, then the rig with the foil has got it all over the one without. I've pulled the foils off at various times for whatever reason - they have never been off long.

"I found this snipet on THT, "Of course they give lift, my point was that the hull should provide the lift rather than the engine--They work, but they address a problem that doesn't belong to the engine..." - One way of looking at it. The other is that the amount of lift generated by a hull is fixed to a point (short of fitting trim tabs) - it has a minimum hull speed below which it just won't work efficiently. Sea conditions are certainly not. Most hull designs are a compromise for a comfortable balance of stability, performance and seakeeping. They aren't designed to go fast in rough conditions despite what the manufacturers and fanboys tell you. The foil is, short of latitudinal correction, a "poor mans" version of trim tabs when installed correctly courtesy of the trim button which creates the variable lift the hull can not. Sure, if you are a diehard or a masochist that doesn't mind a kicking, no foil required but for me at least, that simply isn't the case.

[scottar]

I’ve had some average experiences with these things especially with beam and following seas. And yes I do know how to trim correctly. It made the boat very unpredictable. I wasn’t happy at all and removed it promptly and placed into the recycle bin

Like any bolt on bits - there are always going to be some combinations that simply do not work. What hull, engine, foil package was it Paul?

[TREVELLY]

I have a deep V 6m boat with 175 Suzuki and the boat is a lot more stable (it rolls more side to side without foil - acts like a sway-bar) with hydrofoil and has better hole-shot and cavitates less.

I tried without and got same maximum speed but the performance was definitely inferior without the foil.

So nup - you can't have mine.

$140 from https://www.whitworths.com.au/sport-...ydrofoil-black

[NAGG]

Foils clearly have their place & just sometimes a motor / hull combinations needs some help . My very first boat a 5.35 Quintrex CC with a 75 Mariner would porpoise badly on flat water when running at speed ……. because the boat was light & the pivot point was basically under the driver . There wasn't much you could do - trim all you like you still couldn't stop the bounce . It was suggested that I go with some alloy dolphins & problem solved.
My seajay barramasta was originally fitted with a 70 Yammi ….. never had an issue ( just underpowered when loaded up) - I then upgraded to a 100 yammi & all the sudden there was an issue - we raised the motor 1 notch - not fixed . It was only associated with being trimmed out running at 4500 revs+ on flat water …… went with a an SE400 - problem solved . Sometimes you cant distribute weight ideally or have people stand on their head with one leg out to the side .

Chris