Fellow novice boaters; we are the downfall of scarab!

[the MfM]

What was once one of the most reputable race boat and sport boat brands, now makes floating hot tubs delegated to pulling fat kids on tubes while getting about 1 mile per gallon. What a disgrace.

What Happened to Scarab?: The Fall of a Legendary Boat Brand — Wave To Wave

There was a time not that long ago that the prominent boat brand, Scarab, made a large variety of boats recognized for their racing heritage, design, and style. The brand was very powerful, yet a little confusing.

www.wavetowave.com

 

[buckbuck]

"...as jets suck for most types of boating. Jets are very inefficient, and slow, and their only real advantages are that they are cheap, there are no gears in the driveline (they are just simple pumps) and there is no propeller to hurt anyone when you run them over. That’s about it."
Sounds like the author is an authority on jetboats and runs people over with his prop boat.

 

[zipper]

Interesting read. I like the older Scarab's from the Maimi Vise era, I don't care for many of the Beneteau power boats I see on the Beneteau Owners group on Facebook, they are kinda ugly to me.



But back in the late 80's and early 90's they made some beautiful sailboats.

 

[the MfM]

Interesting read. I like the older Scarab's from the Maimi Vise era, I don't care for many of the Beneteau power boats I see on the Beneteau Owners group on Facebook, they are kinda ugly to me.

View attachment 94018

But back in the late 80's and early 90's they made some beautiful sailboats.

View attachment 94019

Well ugly boats are their specialty

 

[Jgorm]

"...as jets suck for most types of boating. Jets are very inefficient, and slow, and their only real advantages are that they are cheap, there are no gears in the driveline (they are just simple pumps) and there is no propeller to hurt anyone when you run them over. That’s about it."
Sounds like the author is an authority on jetboats and runs people over with his prop boat.

I agree with that statement. He just forgot that they rule in shallow water! They are super inefficient and therefore slow for the power they consume. They also get clogged by floating junk. Prop boats are better for most situations that do not involve shallow water. I cruise over 1' sand bars every time i boat.

 

[swatski]

They are super inefficient and therefore slow for the power they consume.

That is simply not true for properly setup and maintained modern (not the Berkeley style) pumps used in cruising range.

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[Beachbummer]

I think his point is that for the powertrain they are slow, compared to similar horsepower jet boat. If I had 2 x 150 Yamaha outboards on my sx230, It would go faster than with the current set up. Maybe substitute "slow" with Not as fast as similarly powered prop. His wording is suspect to make us seem "slow" but his point that it takes more horsepower in the jet to go the same speed has to be accepted to have an honest conversation.

 

[Beachbummer]

They are not for everyone, but jets must have some positive attributes as well or I wouldn't be here. I don't agree with the guy, just playing devil's advocate on his "slow" statement.

 

[BigAbe75]

I think his point is that for the powertrain they are slow, compared to similar horsepower jet boat. If I had 2 x 150 Yamaha outboards on my sx230, It would go faster than with the current set up. Maybe substitute "slow" with Not as fast as similarly powered prop. His wording is suspect to make us seem "slow" but his point that it takes more horsepower in the jet to go the same speed has to be accepted to have an honest conversation.

Wouldn’t that 150 OB likely have a larger prop and move more water, too? Do we need the higher HP and higher rpms to move the same volume of water at a faster rate producing the push?

For us, it’s the velocity and volume of the water coming out of the tube that generates the push, and not the actual prop moving through the water as in other types of propulsion?

(I’m actually trying to learn, here, from any willing to share. I’m not sure how solid my understanding is of the actual mechanics of what makes our boats go.)

 

[GTBRMC]

It is true that with a jet most hulls lose some top speed vs same setup with a prop.

Top speed is only one aspect of performance. How many times does anyone ever drive their car at top speed? How many times does your car's drivetrain make a difference at a stoplight, on a freeway ramp, while towing a load, etc? Overall performance on most of today's jets compares very favorably with other options: holeshot, time to plane, time to 30 mph, etc.

Also, fuel economy on the twin engine jetboats I know is very favorable vs prop boats with similar power.

Also, the overall simplicity of the jet drive dramatically reduces total cost of ownership and dramatically increases reliability. In eight years of ownership I never lost a single minute of planned boating time due to mechanical problems. How many prop boaters can say that?

Edited to fix typo.

 

[Jgorm]

I think his point is that for the powertrain they are slow, compared to similar horsepower jet boat. If I had 2 x 150 Yamaha outboards on my sx230, It would go faster than with the current set up. Maybe substitute "slow" with Not as fast as similarly powered prop. His wording is suspect to make us seem "slow" but his point that it takes more horsepower in the jet to go the same speed has to be accepted to have an honest conversation.

Exactly. Twin 150s would probably do 65mph and yank a single skier up, all while making half the noise. My boat wasn't happy pulling up a single ski, and he's only 140lb. Put a 150 outboard on my mr1 waverunner and it would probably do 70mph instead of 50. Compare the v drive boats to jet boat with the same engine and it's comical. If jets were more efficient, every boat would have one. I'd have a v drive if i didn't have sandbars, but if you beach one of those your mega screwed. Yamaha is a great designed boat, but there are lots of reasons why 95% of boats in deep water have propellers. At the end of the shallow Colorado River where i boat, it's probably 50%+ jets because you can blast over sandbars.

 

[swatski]

Pleasee...

Some of the issues you and other mention (check The Hull Truth, lol) are pretty specific to jet drives used in outboards' lower units, which is a completely different situation that Yamaha jb hamiltons so let's not confuse those. The hamiltons (like our pumps) are volume pumps and will carry a much heavier load then say an american turbine which is a pressure pump, and get way, way better fuel economy. All boat propulsion systems are sensitive to engine and propulsion unit mismatch, jet or propeller mismatch alike results in poor performance and inefficient fuel consumption, but the jet drives attached to outboards are usually not well matched at all.

The jet pump advantages are indisputable in most categories:

"Zero speed - maximum thrust" ascertain absolutely superior acceleration and steering, and "power breaking" ability, too.

The reverse is exellent on our pumps compared to stern or V-drives!!! And so is maneuverability, with no transmission you can do just about anything with them at any throttle setting.

The fuel efficiency and performance of a jetboat can be affected by anything that disrupts the smooth flow of water through the jet unit. Not just a plastic bag sucked onto the jet unit's intake grill, but inefficient sealing of the tunnel or pump segments can have quite an adverse effect.
Yes, unfortunately, Yamaha sucks where is comes to QC, but their engine/drive/pump design is superb: simple and efficient (when properly setup, tuned and maintained).

Plus of course all the other advantages of jet drives like safety and shallow water capability.

Jet disadvantages are there, too:
Wet splitting is iffy, so if I had to wet slip in the ocean I would 100% chose an o/b.
No lifting strakes or chines or stepped hull possible due to intakes under hull sucking air.
Clogging in algae infested waters etc.


EDIT: as far as the noise - it is totally dependent on how you want to deal with it. In my case, it took a while and a lot of effort but my AR240 is QUIETER than most of my friends inboards. Fact.

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[OrangeTJ]

Reverse is superior on jets vs props? That is 100% opposite of my experience. I found reverse power to be very limited due to the fact that the thrust is as much down as back and too much of it results is severe cavitation. That said, every system has advantages and drawbacks. Acceleration is a big upside with jets but they tend to lack top speed compared to an OB or stern drive all else being equal. V drives aren’t great for top speed either due to thrust angle.

 

[swatski]

Reverse is superior on jets vs props? That is 100% opposite of my experience. I found reverse power to be very limited due to the fact that the thrust is as much down as back and too much of it results is severe cavitation. That said, every system has advantages and drawbacks. Acceleration is a big upside with jets but they tend to lack top speed compared to an OB or stern drive all else being equal. V drives aren’t great for top speed either due to thrust angle.

I meant to say jet vs inboards with the reverse, in my experience inboards just want to go one way in reverse (right?)...

But the "power breaking" is for real, and that is an amazing capability. Except of course in E-series Yamaha where it is electronically disengaged...

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[buckbuck]

 

[Julian]

The author is an idiot. Barely worth responding to. At one point in his article he says jets suck, then he says Scarab used to build some nice jets....which is it?

He's just lamenting the old days of cigarette sytle Scarabs. They went out of business making those boats because the market for them was simply too narrow. Not enough people wanted very expensive boats with shitty space utiliztion that only did one thing....go fast. Blame their moronic Product managers for their demise not jet boats! Idiot.

 

[Jgorm]

Reverse is superior on jets vs props? That is 100% opposite of my experience. I found reverse power to be very limited due to the fact that the thrust is as much down as back and too much of it results is severe cavitation. That said, every system has advantages and drawbacks. Acceleration is a big upside with jets but they tend to lack top speed compared to an OB or stern drive all else being equal. V drives aren’t great for top speed either due to thrust angle.

Agreed to all except the v drive statement. They can do 300mph. All the fattest boats are v drive.

 

[haknslash]

Funny you post the video. I'm currently sitting here watching some boat drags on TV.

 

[OrangeTJ]

Well ok - just a bit different than most recreational boats! Don’t those also run surface piercing props?

 

[Jgorm]

Some do, some don't. They are fairly common in socal lakes. My comment was that the v / or direct drive is the go to for all the fattest boats, including turbine powered race boats. It's also the only option on most boats over 30'. The angle doesn't make them slow at all.