ventilated v-hull safety

[ECeptor]

Check out Velocity's opinion on the subject (scroll to bottom of page):
http://www.velocityboats.com/Safety.html
So, is this "safety risk" real or marketing hype?

[Kilrtoy]

Guess ya'll better sell them boats.....
and buy a velocity

[Havasu Hangin']

Steve Stepp (pardon the expression) has been preaching the benefits of pad bottom lift over steps for a loooong time... :sleeping:
IMHO, pad bottoms seem to land a little harder than true V's.

[CornWater]

Check out Velocity's opinion on the subject (scroll to bottom of page):
http://www.velocityboats.com/Safety.html
So, is this "safety risk" real or marketing hype?
I would have to say a little of both..

[OGShocker]

That is one of the BIG reasons we chose Dana Boats as our builder. NO STEPPED hull! For the two to three MPH gains a stepped hull provides, the dangers outweighed the need for speed. Our Dana can hook a 60 MPH turn in veried conditions when it needs to.

[Kilrtoy]

Can someone explain the differences of the two hulls and how it affects the handling of the boat

[Havasu Hangin']

Can someone explain the differences of the two hulls and how it affects the handling of the boat
A pad bottom lifts the hull out of the water to create less drag. On the bottom of the keel, near the transom, the "V" will flatten out. This flat area acts like a wing (creating lift).
A stepped hull has...well, steps, that induce turbulance under the hull creating lift.

[XTRM22]

Can someone explain the differences of the two hulls and how it affects the handling of the boat
I'd like to see some informed explainations on this myself. My 22' Extreme has a delta pad, but was also offered with a single step as an option. My simpletons understanding is that the step really just creates a bond breaker with the waters surface. Theoretically I guess it's a faster hull but also logically seems it might be more apt to break loose sideways in a turn. I also think to say a stepped hull is less safe then a non-step hull is crazy. I've driven both, and I think you can feel the diference, but it's just not that big a deal.
Chuck

[XTRM22]

A pad bottom lifts the hull out of the water to create less drag. On the bottom of the keel, near the transom, the "V" will flatten out. This flat area acts like a wing (creating lift).
A stepped hull has...well, steps, that induce turbulance under the hull creating lift.
SO if you have both and enough HP to get it up on the Delta pad are the steps doing anything? Seriously, I've seen the Crownlines or Searays with "serpentine" steps that to me look like they'd be dry if you were really planing right.
CHuck "showing confusion publically" XTRM22

[Jbb]

Jeff ....Have you ever seen a stepped hull slide in a turn......I have seen a couple of Fountains spin hard in a turn.....And although not exactly my favorite with styling points...The Poker Run In Jacksonville usually brings about 35 of them together...Including Stepp himself..... and those hulls respond VERY well to bigger power.....

[Havasu Hangin']

SO if you have both and enough HP to get it up on the Delta pad are the steps doing anything? Seriously, I've seen the Crownlines or Searays with "serpentine" steps that to me look like they'd be dry if you were really planing right.
CHuck "showing confusion publically" XTRM22
That's the big question. Some guys think that the steps are useless, and others swear by them. I think the guys on OSO said they were first used on 1920's sea planes...so the technology is not new.
I think the smaller boats can get pretty high on the pad, but the bigger ones still have quite a bit of bottom getting wet at speed. I think everyone agrees that it is a tradeoff (straight away speed for some corner handling sacrafice).
I'm told don't turn a step bottom boat with the drives in- it'll bring the ass-end around. A true V like mine (or a Velocity) will just carve the turn.
Jeff ....Have you ever seen a stepped hull slide in a turn......I have seen a couple of Fountains spin hard in a turn.....And although not exactly my favorite with styling points...The Poker Run In Jacksonville usually brings about 35 of them together...Including Stepp himself..... and those hulls respond VERY well to bigger power.....
I've been in a cat that slid and hooked...but not a V.
I do not know anyone with a Velocity boat, so I can't really comment on his hulls. From what I read...he dosn't like steps very much. However, I have ridden in pad bottoms, and they seem to be fast, but they seemed to land a little rough in the big chop (then again, I'd really need to ride in a non-pad version to compare apples to apples).

[dicudmore]

That is one of the BIG reasons we chose Dana Boats as our builder. NO STEPPED hull! For the two to three MPH gains a stepped hull provides, the dangers outweighed the need for speed. Our Dana can hook a 60 MPH turn in veried conditions when it needs to.
I second that.....no steps on my boat :wink:

[cola]

My 29 Essex has a pad about 8' long. No step. The 25' Essex just added a step to there bottom & I have not ridden in one yet. Hot Boat says it is 3-5 mph faster then the botton without. Who knows, were just having fun.
Late, Mike :cool:

[LHC30Victory]

We have a triple step on our 30 Victory and have not had any problems with slipping or coming anyway loose in turns. Of course, we were told not to tuck the drives in during a turn and that has been expanded on in threads at Offshoreonly.com.
Safety point? Absolutely! Like many things when operating your boat - Know the boat and what it does under the circumstances.

[Kilrtoy]

Ok Im lost!
Why dont you trim your drives down while turning.....

[AirtimeLavey]

Maybe lifts/lightens the rear and poss. result in slide or spin-out? :idea:
I just bought a Lavey w/steps. No experience in it yet. Been driving a jet for 3 years, and love sliding it around. It's the hooking and rolling thing on the V that concerns me. Not too concerned, though. I try to know/stay within my limits.

[redneckgirl]

Ok Im lost!
Why dont you trim your drives down while turning.....
Kilr... with the step bottom you must trim down to turn or you can slide. :jawdrop: With the step you just learn to trim down on turns!!! Have you not driven a SW with the step??? I know you want a bigger boat... but you can drive our boat next time we see you!!!! :D :D
RNG

[phebus]

I have a cat with steps, and it is my first cat. I always turned the v bottoms I have had with the trim down, and have continued that practice with the cat. I am going to have to try turning with a neutral trim and see how it does. It would be a hard thing to learn, I am just so used to trimming and turning.

[Kilrtoy]

Kilr... with the step bottom you must trim down to turn or you can slide. :jawdrop: With the step you just learn to trim down on turns!!! Have you not driven a SW with the step??? I know you want a bigger boat... but you can drive our boat next time we see you!!!! :D :D
RNG
What Im reading is you dont trim in, it will cause you to spin out.
On my little boat with no steps, it turns on a dime when you bring the drives down / in. When you leave them up, it wont turn very well....

[redneckgirl]

What Im reading is you dont trim in, it will cause you to spin out.
On my little boat with no steps, it turns on a dime when you bring the drives down / in. When you leave them up, it wont turn very well....
With a step, the bow need to be in the water to turn... if it is out you will slide!!! It is the same as yours!!! The Shockwave Step Skier was alot different than our old boat... speed and step!!!! It makes you think about what you are doing!!!! But is in no way unsafe, unless you are an idiot!!! :D
By the way you need to make the Naci Boat Bash!!!
RNG

[Kilrtoy]

With a step, the bow need to be in the water to turn... if it is out you will slide!!! It is the same as yours!!! The Shockwave Step Skier was alot different than our old boat... speed and step!!!! It makes you think about what you are doing!!!! But is in no way unsafe, unless you are an idiot!!! :D
By the way you need to make the Naci Boat Bash!!!
RNG
We were thinking about it , but that is along drive to go to havasu to get the boat, to go up there, to go back to havasu to drop off boat and then come home...To much work....

[LHC30Victory]

With a step, the bow need to be in the water to turn... if it is out you will slide!!! It is the same as yours!!! The Shockwave Step Skier was alot different than our old boat... speed and step!!!! It makes you think about what you are doing!!!! But is in no way unsafe, unless you are an idiot!!! :D
By the way you need to make the Naci Boat Bash!!!
RNG
Sorry to disagree RNG, but with the trim down, the stern is lighter and the front digging more (respectivly), with the steps creating a "riding on marbles" effect, you are more likely to slide! DO NOT TRIM DOWN IN TURNS WITH A STEP BOTTOM! If you trim up, the boat sets harder on those marbles.
Try this thread for more info:
http://www.offshoreonly.com/forums/showthread.php?t=26781&highlight=stepped+hulls

[AirtimeLavey]

Sorry to disagree RNG, but with the trim down, the stern is lighter and the front digging more (respectivly), with the steps creating a "riding on marbles" effect, you are more likely to slide! DO NOT TRIM DOWN IN TURNS WITH A STEP BOTTOM! If you trim up, the boat sets harder on those marbles.
Try this thread for more info:
http://www.offshoreonly.com/forums/showthread.php?t=26781&highlight=stepped+hulls
Thanks for the link. Like Kilrtoy, I been reading a lot about it. Seems like most agree w/you. They also say, not to back off the throttle, and... it all comes down to know your boat. Fortunately, I don't anticipate throwing a lot of sharp, high speed turns. :squiggle:

[Kilrtoy]

RNG,
You may want to read that thread(LINK) and it will change the way you drive your stepped boat....

[LHC30Victory]

Education and Safety is Job #1.
These boards are one of the best ways to share information - both heard and learned :skull:

[THOR]

Wow. I must be 'doomed' since I have not only one, but two steps in my hull. :cool:

[Roxysnow]

Nice thread! Just another way to scare the crap out of the ladies! Wait maybe I can get a new boat out of this? :confused: Anyways, I am sure not everyone out there are making U turns at 60mph...... You got to know your boat. If a step is so dangerous then you all with CATS are f%&ked! It's just another way to market a boat! Again, learn your boat! :D

[ECeptor]

Wow, this a much better response to the question that I thought it would get!
OK - I did a little search and the first stepped bottoms date back the the late 1800's. The step is a dramatic reduction in the cross section of the boat bottom which forces air in to fill in the void. This allows the hull to ride on these "air marbles" which reduces drag. The longer the boat, the more steps can be added. These air marbles are what, supposedly, allow the boat to spin out while cornering.
Everyone knows a flat bottom boat has less drag on plane than a deep-V. So a "pad" is essentially a flattening of the hull at the very most rearward portion. It makes sense that this would both add speed and make the ride a little rougher in big water.
What got me thinking about this subject again was the movie "6 days, 7 nights" with Harrison Ford was on TV. If you notice the sponsons they took off the old WWII fighter they found in the jungle, they had stepped bottoms!
For what it's worth, if I had the extra $$$ I'd own a Superboats Y2k - which has a stepped bottom.

[Dusty Times]

Treat them with respect as you would any high performance boat and you'll be fine.
Tuck the drives in and slam it into a turn and IT'S BATH TIME!

[Bob Hostetter]

ECeptor,
You are right in your understanding on how a stepped hull works. The induction of air under the hull between the water and the hull reduces friction allowing maxi speed for a given hull design and power level. They are very stable in a straight line, but the friction reduction can create problems when the boat is in a high "G" turn, especially at higher speeds. The back (transom) of the boat is more likely to wash out, breaking free from the water and spinning out. If during the spin the keel line of the hull graps the water the boat will try to roll over towards the outside of the turn. The high injury rate is the result of the driver being ejected to the outside of the turn and the boat rolling over them.
A pad hull design requires enough power from the boat to get the hull up on the pad. Once that happens there is a marked decrease in friction and as a result a noticable increase in top speed. The pad hulls are fairly stable and predictable in turns but have some problems in straight line high speed running. Once the boat is on the pad, any side to side forces such as a roller coming in from the side can upset the hull and cause it to fall off the pad to the side. If this happens, especially if the hull has sharp or pronouced chimes, it can hook a chime causing a very sudden left or right hand turn. As you might guess this can cause the driver to be ejected from the boat.
Both stepped and pad 'v' bottomed hulls have advantages over a standard 'v' design, (more speed capabilities) but they also have disadvantages. Because of the inherent chiming problems with pad style hulls you don't see them much in off shore racing where surface conditions can be severe and unpredictable. You mostly see them on smaller boats used for striaght line speed such as single engine drag O/B's. A further development of the pad concept is the dropped center keel you see on tunnels, especially jets.

[Havasu_Dreamin]

My 29 Essex has a pad about 8' long. No step. The 25' Essex just added a step to there bottom & I have not ridden in one yet. Hot Boat says it is 3-5 mph faster then the botton without. Who knows, were just having fun.
Late, Mike :cool:
I had heard that Essex was/is also going to add a step hull bottom to the Alandra.

[spectras only]

[QUOTE=Bob Hostetter]
A pad hull design requires enough power from the boat to get the hull up on the pad. Once that happens there is a marked decrease in friction and as a result a noticable increase in top speed. The pad hulls are fairly stable and predictable in turns but have some problems in straight line high speed running. Once the boat is on the pad, any side to side forces such as a roller coming in from the side can upset the hull and cause it to fall off the pad to the side. If this happens, especially if the hull has sharp or pronouced chimes, it can hook a chime causing a very sudden left or right hand turn. As you might guess this can cause the driver to be ejected from the boat.
Both stepped and pad 'v' bottomed hulls have advantages over a standard 'v' design, (more speed capabilities) but they also have disadvantages. My sterndrive boat has 24 deg deadrise with a V pad with the exact characteristics mentioned here. Be aware of your boat's shortcomings and you'll be alright :D

[Havasu Cig]

That is one of the BIG reasons we chose Dana Boats as our builder. NO STEPPED hull! For the two to three MPH gains a stepped hull provides, the dangers outweighed the need for speed. Our Dana can hook a 60 MPH turn in veried conditions when it needs to.
It is more than a 2-3 mph gain. Our T/G runs about 13 mph faster than a non stepped T/G with the same power. I have run our boat in all conditions you could imagine in both fresh and salt water and have not had a problem. Trim out while turning and don't get out of the throttles. Get to know your boat and don't be stupid and you will be fine.

[ECeptor]

It is more than a 2-3 mph gain. Our T/G runs about 13 mph faster than a non stepped T/G with the same power.
That a huge difference! What top end are you seeing?

[playdeep]

...Steve Stepp has raled against ventilated (step) bottoms for years.
Cigarette,Outerlimits,Fountain,Skater,Eliminator,D CB,have had success with them so I think there must be something that makes step bottoms viable.
My Nordic had a pad and it was actually neat learning how to keep it on the pad at speed,as HH said they (pad bottoms) are prone to land hard.
When I bought my first Eliminator step bottom,I took the same approach as when I bought my first Porsche 911,I knew it had some different handling characteristics,so I took time to learn the boat and car before pushing the envelope.
Half the fun of owning a high performance platform (boat or car) is learning how to master it.
Any boat can bite,if the person operating it isn't careful.

[Dr. Eagle]

Spoken like a boat builder that doesn't want to re-tool...

[Debbolas]

DOC !!!
:wink:

[SoCalOffshore]

Also all manufactureres are not the same with their bottoms. Some stepped hulls are much more stable than others. Most manufactureres have gone to stepped hulls for their speed advantage. Others have not as they have developed other bottoms, such as pad bottoms. Still others, only buy their hulls from other manufactureres and/or are older designs, and as such, do not offer steps. Then Hallet even offers stepped and non stepped hulls for many of its models.

[CJ]

This is one thread I will not be forwarding to my wife so not to scare her.
I must thank you all for these kind of discussions. I never knew the danger of steps and now have 10 hours on my Eliminator. I guess I have always been pretty safe, settling the boat, starting the turn then steadily powering up out of the turn. However, I will definitely be more careful now.
THANKS!

[Havasu Cig]

That a huge difference! What top end are you seeing?
I have seen 83.6 on gps and I know Tres Martin has been getting 85-86 mph with the same boat / motor combo after some dialing in. Not bad for a 38' boat with 500's and a cabin.

[ECeptor]

I have seen 83.6 on gps and I know Tres Martin has been getting 85-86 mph with the same boat / motor combo after some dialing in. Not bad for a 38' boat with 500's and a cabin.
So non-stepped version are running only 70mph with the same power? If so, that's an amazing jump!

[Havasu Cig]

I have been told they run in the 70-72 range. I have been in a non-stepped Tiger which is 42' with 1000's and 6's and the thing runs in the high 90's. You can put 750's in a stepped Gun and run about 110. Big difference.

[ECeptor]

Big difference.
No, huge difference!