Drawbacks of Jet Boats?

[Jlawsen]

Re: Drawbacks of Jet Boats?

Hands down, Yamaha builds the best jet boats on the market. (IMHO) They reworked their engines / pumps to bring RPM down to 7,000 - 7,500 RPM WOT (from 10,000RPM) which results in much better fuel economy (on par with a prop) and better engine life.

As to skinny water, they will go where you wouldn't dare take a prop, period, the end. The only time "Sucking up sand" is a problem is if you are in skinny water and use reverse as the water flow is directed down and forward it will kick up whatever is on the bottom. (Sand / Small rocks) I've ran them in water that wasn't even a foot deep at WOT. Not an issue.

Weeds can be an issue but selecting the proper grate and impelor make a huge difference. Of course most just try to stay away from heavy weeds, just like the prop guys. Maintenace is a breeze compared to anything with a prop. The "drive" could not be simpler.

Handling is different than with a prop at low speeds and MUCH more agile at any planing speed. There IS a learing curve to low speed handling but once you catch on you can do things a prop boat can't. (Make 180 degree turn in the length of the boat.)

One area you didn't mention was water sports but if they are part of the use a jet is MUCH safer for those in the water.


One final note, of all the people I know that bought and used a Yamaha jet boat I've yet to hear one say they didn't love the boat. They can't all be wrong.

Agree, I have a 22' North River Commander with the 502 and a Hami 212 Turbine pump. I also have a stomp grate to clear out the trash bags and weeds and the occasional T-Shirt that seems to always find it's way to the shallow water that I want to be in. From a stand still I need at least 1-1/2' of water and if I trim it just right I can slowly bring it up on plane in that amount of water. Once on plane and at cruise speed 35mph I only need about 6" because my hull has a delta pad. I rarely run at cruise speed in water that skinny unless I know the waterway very well. With a 1/4" thick Aluminum bottom I can go over a lot of stuff that would sink a glass boat but I can tell you first hand, it's not something you want to do unprepared. It'll throw you around pretty good.

For what it's worth, I haven't used that boat all year. I much prefer my smaller JetCraft outboard. It's just easier to handle and has less draft so with the bow mount trolling motor I can get in and out of places that most can't. It's not a skinny water river boat but it makes up for that in other ways.

 

[QC]

Re: Drawbacks of Jet Boats?

A quick story . . . I piloted a friend's 19 footer with a 460 Ford and Berkley pump pulling a Parachute on the Colorado River. There was some wind, and the combination of downwind speed required to keep it airborne, river width and sandbars meant I had really no choice but stay at full throttle and run over whatever got in may way. The issue was where the chute was, not the boat. Never been that committed before, where simply stopping was not acceptable No other way but a jet for that set of circumstances that day. Not to pump myself up, but I missed my only chance at a Parasail/chute ride as I wouldn't do it unless I was at the helm. No one else would either . . . There was, of course, one other solution. No rides. We were all in our 20s, so that was definitely not an option.

 

[haulnazz15]

Re: Drawbacks of Jet Boats?

Well, I would think running on plane would be much less of an issue with a jet in skinny water than running at idle or above when not on plane. The issue is the jet pump doesn't have much time to suck things off of the bottom when its moving across the surface quickly. When at non-planing speeds in skinny water, the boat and the intake grate or much closer to the bottom and drawing water from a narrow volume of water and allowing stirred up debris to cycle through the pump.

 

[Texasmark]

Re: Drawbacks of Jet Boats?

People don't like you, including me and lake front property owners...........

 

[Expidia]

Re: Drawbacks of Jet Boats?

Thanks again for all those comments. I sent a link to this thread to him so he can read the pros and cons himself.
One nice feature from the comments was that a jet boat is safer to own when the boat is used around kids. He does have 4 young chilldren that may be tubing in the future. Even if one falls out of the baot having no prop is a plus.

Another negative is weeds. Not that this lake is socked in with weeds but there are weeds in the shallow areas. This is not the kind of friend that would jump out of the boat, swim underneath it and start pulling weeds from a grate.

His bay is definitely shallow. I had to raise my outboard and paddle just to reach his dock the last time I was there. Alll though this has been a somewhat dry season, so I suspect the water level is higher on average.

 

[Part-time]

Re: Drawbacks of Jet Boats?

I have owned an old school jet boat, an 18ss sidewinder with a 455 Olds and Berkley jet.
My wife has an F14 Sea-raider with a 90hp merc sportjet (3 cyl 2 stroke).
And I'll use my old Sidewinder 16ss with a 1981 175 Evinrude Sport (V-6 2 stroke outboard) for comparison.

-Fuel consumption-

With just 1 person in the boat.
Running WOT all 3 will break the bank in a hurry, but the 18ss is the worst, the 16ss in second and then the F14.
The 16ss tops speeds over 60mph (and is scary as ****:redface: to drive)
The 18ss is sturdy as a rock at 60mph.
The F14 gets about 35mph...

With 4 people in the boat.
The 18ss uses the same amount of gas, and gets about the same performance.
The 16ss now uses about the same amount of gas as the 18ss does and goes roughly 55mph now.
The F14 looses a couple of mph and fuel consumption stays the same.

People in the boat and pulling skiers/tubes/whatever...
The 18ss still doesn't use anymore gas and I can't open it up or I'll end up killing the people getting pulled behind me!!!
I now have to change the prop on the 16ss, use almost twice as much gas as the other 2 boats and have a top end of about 45mph.
The F14's gas millage hasn't changed and gets about 28-30mph.


The reason... a jet boat's engine will always be under the same load at a given rpm no mater how the boat is loaded.

-Safer for swimmers than a prop... any negligent operator can kill someone. A blast from the jet can be deadly!

-Weeds, I have never had to unclog either of mine. But I have had to stop with my 9.9 on my 14' tiney and give it a good rev in reverse to clear the prop a couple of times.

-Idling in shallow water will not suck anything harmful into the pump.
Running WOT in shallows will not draw anything in either.
Hammering the throttle in 3' of water or less can suck stuff up from the bottom.

All in all.... I love my jet boats, and my prop boats, and the glass ones and the tineys and my RIB........:redface:

I guess the biggest variable is what the boat has between the seat and the steering wheel.

 

[Expidia]

Re: Drawbacks of Jet Boats?

This boat on Yamaha's home page was definetly the same model and color that was next to me in the parking lot.

Great looking rig. Interesting too that on their boat comparison chart this model goes for $48k against 71 to 90k for similar prop boats.
http://www.yamahaboats.com/

 

[Expidia]

Re: Drawbacks of Jet Boats?

People don't like you, including me and lake front property owners...........

So why do you say this???

I'm not talking about a jet ski making all their stupid moves in front of shoreline homes at 8am. Or trying to jump your wake behind your boat.

My friend is looking for just a new rig in the 30-50k boat range that can handle his shallow bay and dock.

This Yamaha model is a 23 footer. Is this what you have a problem with as a shoreline homeowner just because it's a jet drive? Are they noisier?

 

[OrangeTJ]

Re: Drawbacks of Jet Boats?

There does seem to be a misconception that jetboats are oversized jetskis. Two totally different things. Our Yamaha SX210 is not all that different from any other 21 foot bowrider, with the exception that it has a lot more space inside and it uses two smaller displacement 4 cylinders mated to jet pumps vs a single V6 or V8 automotive-derivative engine mated to a stern drive. The boat itself is certainly not anything like a jetski or waverunner. Primary differences between the Yamaha and a stern drive in actual practice are that it has no props in the water for the kids to cut themselves on while boarding or exiting the boat and it runs at higher RPM than a comparable sterndrive - 30 mph cruise for us with a full tank of gas and our family of 5 (3 young children) is 6,000 rpm. The engines don't seem stressed in the least at that RPM, though, so you can't compare it to running a v6 or v8 at the same rpm. The RPM does generate some sound, though, so the boat is not as quiet as some of the I/O's I've been on. Ours revs out at about 8200 rpm and runs 45 - 48 mph at that engine speed, depending on loading and conditions. Even at that RPM, the engines don't seem especially stressed, due most likely to it's short stroke layout. The "high output" models will run 55 - 58 or so on the top end. Low speed handling in stock form takes some getting used to, but I sidestepped virtually all of that by installing simple fins that bolt onto the nozzles and provide a bit of a rudder effect. The boat is supremely maneuverable and sits in 18 inches of water at a standstill. We sucked up our ski rope one time, but clearing it was a fairly straightforward exercise of popping out the cleanout plugs, reaching in and cutting away the rope. No need to get into the water to cleanout the pumps. The only thing I don't love about ours is that it needs a lot of revs to run at 7 or 8 mph, which makes that relaxing cruising speed not so relaxing and pretty fuel-intensive. I counter that by just going slower or faster!

Ours looks just like this:
[ATTACH]141078._xfImport[/ATTACH]

 

[OrangeTJ]

Re: Drawbacks of Jet Boats?

sucking up a bungee chord or section of anchor rope will take out the impeller. then again, so will sucking up a few rocks. the fuel economy is one thing, however a jetboat is insured like a jet ski. a $30000 jet ski. that alone was enough for me to cancel my seadoo speedster order a few years back.

Insurance for our Yamaha SX210 runs $400 for the year for very comprehensive coverage. I guess that doesn't seem like all that much to me. Regarding fuel economy, not sure what to compare it to, but a full day of boating tends to run us about a third of the 52 gallon fuel tank. More if we spend the whole day towing wakeboarders and tubes, obviously less if we spend half the day hanging out in the cove. That doesn't seem so bad to me but maybe an I/O would use a few gallons less under similar usage.

 

[QC]

Re: Drawbacks of Jet Boats?

Fuel is worse for sure against an I/O. With that said I don't think $10 - $15 a weekend makes any difference in the grand scheme of this addiction

 

[V153]

Re: Drawbacks of Jet Boats?

Fuel is worse for sure against an I/O. With that said I don't think $10 - $15 a weekend makes any difference in the grand scheme of this addiction

Yes, and just think of all the children you'll save ...

 

[exploring/carolina]

Re: Drawbacks of Jet Boats?

Just purchased a new Sea Doo normally aspirated 155HP 4 cycle Speedster 150 last week. This is my first jet boat and learning about it for now. Breaking in the engine, so have not had it over 30MPH, it's supposed to go close to 50MPH. The 15 foot four seater handles very nicely. The rig with trailer and wet is probably around 2000lbs. My Toyota Tacoma with 4 cylinder handles it easily.

Here's some specs:

"Fuel Capacity 20.25 gal
Engine Fuel injected,
1503 Rotax 4-TEC Displacement1,494ccRated
RPM (Max) 7,300
Fuel Type 87 octane
Cooling Closed-Loop Cooling System
Jet Pump Axial Flow, Single stage Impeller(Material) Stainless steel
(Outside diameter) 155 ? .07 mm
Width (On Trailer) 7' 1"
Height (No Tower) 4' 11"
Length 15' 4" (On Trailer) 18' 5"
Dead Rise 20?
Gross Weight (On Trailer) 2,100 lb
Dry Weight 1,454 lbs
Storage Capacity 14.5 cu ft
Seating Capacity 4
Weight Capacity 715 lbs
Generator 30 amp / 380 W Battery12V
Beam 7' 1"
Draft 12"
Hull Material Composite FRP Standard Vinylester barrier liner
Full fiberglass stringer "

 

[Expidia]

Re: Drawbacks of Jet Boats?

There does seem to be a misconception that jetboats are oversized jetskis. Two totally different things. Our Yamaha SX210 is not all that different from any other 21 foot bowrider, with the exception that it has a lot more space inside and it uses two smaller displacement 4 cylinders mated to jet pumps vs a single V6 or V8 automotive-derivative engine mated to a stern drive. The boat itself is certainly not anything like a jetski or waverunner. Primary differences between the Yamaha and a stern drive in actual practice are that it has no props in the water for the kids to cut themselves on while boarding or exiting the boat and it runs at higher RPM than a comparable sterndrive - 30 mph cruise for us with a full tank of gas and our family of 5 (3 young children) is 6,000 rpm. The engines don't seem stressed in the least at that RPM, though, so you can't compare it to running a v6 or v8 at the same rpm. The RPM does generate some sound, though, so the boat is not as quiet as some of the I/O's I've been on. Ours revs out at about 8200 rpm and runs 45 - 48 mph at that engine speed, depending on loading and conditions. Even at that RPM, the engines don't seem especially stressed, due most likely to it's short stroke layout. The "high output" models will run 55 - 58 or so on the top end. Low speed handling in stock form takes some getting used to, but I sidestepped virtually all of that by installing simple fins that bolt onto the nozzles and provide a bit of a rudder effect. The boat is supremely maneuverable and sits in 18 inches of water at a standstill. We sucked up our ski rope one time, but clearing it was a fairly straightforward exercise of popping out the cleanout plugs, reaching in and cutting away the rope. No need to get into the water to cleanout the pumps. The only thing I don't love about ours is that it needs a lot of revs to run at 7 or 8 mph, which makes that relaxing cruising speed not so relaxing and pretty fuel-intensive. I counter that by just going slower or faster!

Ours looks just like this:
[ATTACH=CONFIG]167188[/ATTACH]

Thanks for this post. I sent it to my friend. This post was exactly the type of input he was looking for. And thanks for the pic too.

 

[Expidia]

Re: Drawbacks of Jet Boats?

Exploring carolina: thanks for posting the specs and all these pics. Beautiful boat! This is the type of jet boat I pictured when my friend asked me what I thought of jet boats. This style to me is like a jet ski on steroids .

I didn't even know they made jet boats on the style of a deck boat until I was parked next to a new yamaha. The poster above commenting on his new yamaha is closer to what my friend might be in the market for since he has 4 small children.

Your boat is definitely designed to have some fun on though, Congrats and welcome to iboats

 

[Mason78]

Re: Drawbacks of Jet Boats?

I have nothing against jet...I am actually considering a Yamaha for my next boat.

But I do think the safety advantages of a jetdrive are often hyperbolized.

My children and family members have been tubing and skiing with a prop boat for years and we have never had a "prop injury". The kids are taught to be careful around the prop and the engine is turned off when exiting/boarding the boat.

If I do decide on a jetdrive for my next boat I would still insist that the engine be turned off when exiting/boarding. The danger is not only a spinning prop, but that the throttle could be bumped while swimmers/skiers are nearby.

With that in mind I believe the safety advantages are minimal at best.

 

[dwoodwo1]

Re: Drawbacks of Jet Boats?

I have nothing against jet...I am actually considering a Yamaha for my next boat.

But I do think the safety advantages of a jetdrive are often hyperbolized.

My children and family members have been tubing and skiing with a prop boat for years and we have never had a "prop injury". The kids are taught to be careful around the prop and the engine is turned off when exiting/boarding the boat.

If I do decide on a jetdrive for my next boat I would still insist that the engine be turned off when exiting/boarding. The danger is not only a spinning prop, but that the throttle could be bumped while swimmers/skiers are nearby.

With that in mind I believe the safety advantages are minimal at best.

Accidents tend to happen when mistakes are made. It is great to have planned safety procedures, but safety procedures arent always followed and mistakes do happen. it is always better to have a situation where something "cant" happen. I do think the non-existence of a prop is a safety feature, as those accidents definitely do happen.

 

[jkust]

Re: Drawbacks of Jet Boats?

Here is a good head to head set of tests comparing sterndrives to Jet-drives. They each excel in different categories with the I/O winning for fuel economy, overall ride with the ability to trim the engine and tow sports among others. The jet wins for acceleration, and safety among its attributes.
http://www.boatingmag.com/engines/jet-drive-vs-sterndrive

If my water called for it, I'd have no problem with a jet.

 

[jfried]

Re: Drawbacks of Jet Boats?

Accidents tend to happen when mistakes are made. It is great to have planned safety procedures, but safety procedures arent always followed and mistakes do happen. it is always better to have a situation where something "cant" happen. I do think the non-existence of a prop is a safety feature, as those accidents definitely do happen.

You can also make the case that accidents are more likely to happen when those involved don't think it can.

With a prop in the water, the danger is ever apparent -- so that engine better be off, or at the very least, ensure that it doesn't get bumped into gear. With a jet boat, one can get complacent, and there are lots of ways for somebody to get hurt in the water around a boat where the motor is on -- jet or prop.

 

[QC]

Re: Drawbacks of Jet Boats?

You can spin this safety stuff a lot of ways.

1) Kids don't learn prop safety around a jetboat as they grow up. Take trip with other family that has an I/O and they dive off the stern first stop with new family.

2) Kids swim under boats all the time, jet boat driver starts boat, hits throttle sucks kid onto grate and drowns him.

3) Tight turn at high speed retrieving skier near other boat. Aggressive maneuver to insure safety of down skier. Jet boat loses power in turn, boat goes straight, hits other boat.

Please be safe with your paddles on your row boat. Start there, we'll all be good.