Jet Boats vs Outboards and IOs

[Jetboaters]

Curious if the other Jet Boat owners (or those considering one) have a particular driver in what interests them in a Jet boat. For me it was initially the fun of driving it, but then when I had kids the safety factor became my primary driver. The shallow water draft ability is nice, but as others have pointed on on threads here like this one:

http://forums.iboats.com/boat-topic...2013-year-jet-drive-592861-4.html#post4120819

Jet boats can suck things up just as easily as a prop can hit the bottom. I've sucked up a rock before when I idled over a rock pile. It did no damage - if I'd had my old I/O it would have almost certainly bent my prop...so there is something to be said for the difference between lifting something off the bottom and intaking it vs striking the bottom.

Scarab just came out with a Jet, and others are following suit....it will be interesting to watch.

I also like the almost zero bow rise of a jet, but that is a nice to have not a needed feature. The swim deck/patio area on most jets (in particular the Yamaha's) is an awesome place to hang out.

The most common complaints about jets are slow speed steering and fuel economy. Slow speed steering is indeed a down side of jets, but something one can learn to deal with--the offset is amazing high speed steering!

Gas mileage....some variances-inboard (which for safety are comparable do worse):
3.39 MPG at best range for an Yamaha SX240.
3.78 MPG for Cobolt 240
3.83 MPG for Chapparal 224 at best range 3.83 MPG (and yes...the Chap has less wetted area).
2.25 MPG for Mastercraft X-45
3.09 MPG for Tige RZ4

I just picked similar boat lengths of brands that my friends have. It is correct that Jet boats aren't as economical at no wake speeds....(3.93MPG for the shorter Chapparel 224, and 1.29MPG for the Yamaha).

I love the performance and handling of a Jet Boat....just so much fun to drive! Pair that with a boat that is so much easier to maintain and is safer, and I love it! I change the oil and plugs and grease her and that is it! No water pumps!!! WOOT! No transmission! Never had to replace an impeller or wear ring (11 years now). I hated my I/O and winterizing was a PITA!

Every boat type has its pros and cons. I am a jetboat fan....so I'm biased, but I've owned I/Os and OBs too.

I have a family and child and LOVE the safety of a jet boat!!! No exposed prop to strike you, no engine in the way, no prop to worry about kicking etc. Big factor for families that love water sports. That said, an inboard achieves this too.

But like all have said....each boat has its pluses and minuses. Jet boats aren't for everyone.

I like them so much I'm a member of a jetboaters forum but I love to hear other perspectives on Jets and OBs etc.

The one thing I wish my jetboat was better at was use as a fishing platform. I don't fish much, but my daughter likes to. And without a skeg, in a breeze it is harder to track around a back bay with a trolling motor.

FYI--I currently own a 2005 Yamaha SX230, owned a Yamaha LX210, and an Imperial 20' IO before that.

 

[H20Rat]

Re: Jet Boats vs Outboards and IOs

I've owned numerous types of all 3 drives. Still own 2 outboards and 1 jet. Jets have their place, in some conditions they are the best fit, in others, they aren't. (Pretty much like any other boat, a compromise!) The one thing that I've learned is 99% of what people think they know about jets are based on big block berkeley jet pumps, not modern jets, or are hearsay from what they think they know...

Your post is spot on, although I'd say that low speed handling of a jet FAR exceeds a single screw conventional drive. I can walk my single engine jet boat straight sideways, or spin it around in its own length. No single screw prop boat can do that, period.

 

[agallant80]

Re: Jet Boats vs Outboards and IOs

I like the deck layout of the jet better due to the motors being lower and creating more space on the deck. I also like how there is no gimble, bellows etc.

 

[Chris1956]

Re: Jet Boats vs Outboards and IOs

Gee, Don't you think hitting your kid with a prop comes under the heading "stupid human tricks"? Do you need a Jet Boat to avoid doing that?

The biggest downsides to a jet boat is the 30% efficiency loss over a prop, and the lack of steering ability under low or no thrust conditions. I can steer my OB boat, even when in neutral, provided there is some forward motion.

Winterizing an OB is easier than winterizing a Jet Boat, IMHO.

 

[Jetboaters]

Re: Jet Boats vs Outboards and IOs

Gee, Don't you think hitting your kid with a prop comes under the heading "stupid human tricks"? Do you need a Jet Boat to avoid doing that?

The biggest downsides to a jet boat is the 30% efficiency loss over a prop, and the lack of steering ability under low or no thrust conditions. I can steer my OB boat, even when in neutral, provided there is some forward motion.

Winterizing an OB is easier than winterizing a Jet Boat, IMHO.

I don't think anyone hits their kid with a prop on purpose...its called an "accident". Also, its not always the owner...but a guest driver. Add to that the number of kids that do dumb things....and accidents happen. Know of a Jetboater who's daughter was (improperly) sitting on the bow rail. They hit a wake, and she fell overboat and was run over by the boat. He immediately killed the engine-she popped up behind the boat without a scratch. There are similar stories of this happening on prop boats with much different outcomes. BUT---your point is well taken...why was she on the bow rail? Bad captain. But as accidents happen, I like to reduce the risks.

Winterizing an OB is similar to a jet in many respects. Fog the engines, lube and remove/replace the lower unit fluid (except jets don't have any). That alone makes it easier to handle a jet....even with twin engines (spray/spray - lube/lube and put her to bed).

How are you defining efficiency when you say 30% loss? I'm not disagreeing, I just love to see pure data. The MPG data doesn't show that - and that is a measure of efficiency. Are you referring to top speed per HP or what?

@smokingcrater....you are correct...single screw handling, especially inboards takes some practice!

 

[BigDfromTN]

Re: Jet Boats vs Outboards and IOs

Not agreeing with or arguing with anyone on here.

BUT I have also HEARD that when a jet pump is added to the bottom of an outboard you lose about 30%. I don't know how true it is but seems to be a common conception. Nor do I know if they mean fuel use or speed loss or what.

Many folks over in Arkansas use the jet pump on an outboard on some of the rivers there for fishing etc. Many shallow sand and gravel bars in those rivers.

Your summary of one vs other sounds spot on to me.

 

[haulnazz15]

Re: Jet Boats vs Outboards and IOs

BUT I have also HEARD that when a jet pump is added to the bottom of an outboard you lose about 30%. I don't know how true it is but seems to be a common conception. Nor do I know if they mean fuel use or speed loss or what.

That is true, but that's not really the type of jet pump that modern jet board use. The loss in horsepower in the situation you described is largely due to losses due to the design itself not being efficient related to being an afterthought to modify the O/B lower unit.

The newer jet pumps are better in efficiency, but still fall behind traditional inboard or I/O, primarily at low speeds and extremely high speeds. You have to remember that most modern jet boats are turning a smaller impeller at high RPMS. Jet boats have great acceleration out of the hole, but will not be as fast an O/B or I/O of the horsepower, length, and hull design. For instance, a newer Yamaha 212 will run 49mph top end with 360HP (twin 1.8L's), while a Stingray boat with 260HP will run over 50. Give that Stingray a 5.7L MPI (300HP), and it'll run almost 58+.

 

[Sharp Shooter]

Re: Jet Boats vs Outboards and IOs

I've been around both jet and prop boats all of my life. I've never been hit by a prop or known of anyone that has. You would have to be pretty careless or maybe drunk for that to happen.

The 30% loss in efficiency statement is ridiculous. Jet pumps in the modern world are setting records at the races and some of todays largest and most expensive yachts are jet powered and don't forget their use in the Navy.

 

[25thmustang]

Re: Jet Boats vs Outboards and IOs

Sharp Shooter consider that lucky, I was at a wake for an aquaintance that lost his life to being caught by a prop. Not condoning a jet or saying props are all bad, but it does happen.

 

[Sharp Shooter]

Re: Jet Boats vs Outboards and IOs

Sharp Shooter consider that lucky, I was at a wake for an aquaintance that lost his life to being caught by a prop. Not condoning a jet or saying props are all bad, but it does happen.

I don't consider it lucky, I consider it normal. I also don't consider it lucky if I survive crossing the street or mowing my yard even though people sometimes manage to die doing either....

We expose ourselves to dangerous things on a daily basis from kitchen knives to driving our cars, so should we be careful around known things that can harm us (common sense) or should we all just surrender to paranoia and live in a bubble?

What were the circumstances around your friends err aquaintance's accident? Alcohol involved or maybe a lapse in judgment or focus? There has to be some explanation because props don't just attack people.

 

[Alwhite00]

Re: Jet Boats vs Outboards and IOs

One of the boat mags last month tested 3 Glastrons. one jet, one ob & one I/O and if i remember corectly they like
d the ob overall.

I dont think they make a 25 foot cruiser with a jet so i went I/O

 

[Chris1956]

Re: Jet Boats vs Outboards and IOs

Anyone remember when OMC tested a "propguard"? It was a circle piece of 1" X 1/8" (or so) metal around the prop blade edges (kinda like the jet boat impeller housing, but only 1" long), that protected against someone contacting the prop with a foot or hand. They abandoned it do to too much loss of efficiency. Has that issue been solved by modern jet boats?

 

[25thmustang]

Re: Jet Boats vs Outboards and IOs

I don't consider it lucky, I consider it normal. I also don't consider it lucky if I survive crossing the street or mowing my yard even though people sometimes manage to die doing either....

We expose ourselves to dangerous things on a daily basis from kitchen knives to driving our cars, so should we be careful around known things that can harm us (common sense) or should we all just surrender to paranoia and live in a bubble?

What were the circumstances around your friends err aquaintance's accident? Alcohol involved or maybe a lapse in judgment or focus? There has to be some explanation because props don't just attack people.

I agree 100%, props don't go around killing people. Also no need to live in a bubble. However if one if your boating concerns is a prop that could harm/injure someone, then a jet boat is an alternate. I don't think I said we should live in a bubble for fearing a prop... If that's how it came off, it's not what I meant.

I don't have all the details of the accident. Other than he was on a jet ski, and got caught under a friends boat.

 

[Sharp Shooter]

Re: Jet Boats vs Outboards and IOs

I agree 100%, props don't go around killing people. Also no need to live in a bubble. However if one if your boating concerns is a prop that could harm/injure someone, then a jet boat is an alternate. I don't think I said we should live in a bubble for fearing a prop... If that's how it came off, it's not what I meant.

I don't have all the details of the accident. Other than he was on a jet ski, and got caught under a friends boat.

Right on!

Hey I see you have an LX mustang.

I had 2 that I bought brand new and then played with them some. 86 and an 88. Great cars!!

 

[UncleWillie]

Re: Jet Boats vs Outboards and IOs

A Jet Drive is a big plus for Wake-Surfing where the rider is sometimes only 3 feet behind the Boat and could fall into a prop.

 

[Jetboaters]

Re: Jet Boats vs Outboards and IOs

Anyone remember when OMC tested a "propguard"? It was a circle piece of 1" X 1/8" (or so) metal around the prop blade edges (kinda like the jet boat impeller housing, but only 1" long), that protected against someone contacting the prop with a foot or hand. They abandoned it do to too much loss of efficiency. Has that issue been solved by modern jet boats?

That is a completely different configuration than a modern jet pump. A jet pump needs a properly configured intake to load the pump well....wrapping a piece of metal around a prop and calling it a jet is absurd.

There are lots of people wishing that someone made a smaller cabin cruiser with jets....unfortunately they don't yet....Hinckley are the closest thing so far...and they are out of most people's price range!

Hinckley Jetboats - Luxury Jetboats, Picnic boats, Downeast Boats by Hinckley Yachts

To suggest that the desire for a safer configuration is submitting to paranoia is also silly. People make mistakes, if technology can make a boat that is MORE fun to drive AND safer - I'm all over it!

Tell me a prop boat could do this, and that this doesn't look like some serious fun!!!!

https://www.youtube.com/watch?v=X2Iyw5LFrJs

 

[Chris1956]

Re: Jet Boats vs Outboards and IOs

Obviously a prop guard is not a jet. I never claimed it was. I was simply trying to describe for those who have never seen it. The propguards predate Jet Outboards.

No one has yet described how the efficiency of the modern jet boat has been improved. Intrinsically, it would seem that a jet boat would have a disadvantage in efficiency, since the jet pulls in and accelerates water, which then pushes on the large body of water. I would think the efficiency loss would be in the pulling of the water into the tube, the friction of the tube, and the need to push water with water, rather than directly with the prop blades.

 

[Sharp Shooter]

Re: Jet Boats vs Outboards and IOs

A Jet Drive is a big plus for Wake-Surfing where the rider is sometimes only 3 feet behind the Boat and could fall into a prop.

Sorry, I couldn't resist. and keep in mind most wake board and ski boats (which are best for towing) have their props "under" the boat where you can't simply fall on it.

 

[Sharp Shooter]

Re: Jet Boats vs Outboards and IOs

Obviously a prop guard is not a jet. I never claimed it was. I was simply trying to describe for those who have never seen it. The propguards predate Jet Outboards.

No one has yet described how the efficiency of the modern jet boat has been improved. Intrinsically, it would seem that a jet boat would have a disadvantage in efficiency, since the jet pulls in and accelerates water, which then pushes on the large body of water. I would think the efficiency loss would be in the pulling of the water into the tube, the friction of the tube, and the need to push water with water, rather than directly with the prop blades.

Modern jet boat efficiency has improved dramatically or they wouldn't be able to go 141 mph without blowers or turbos. Just sayin.

 

[WIMUSKY]

Re: Jet Boats vs Outboards and IOs

I see a big ol' air intake, sure it isn't blown?

Now here's some tail:

244 MPH Nitro drag boat - YouTube