Diesel engine & dinghy

I took care of and ran a 14' Nautica with a yamaha gas inboard/jet. It was very poorly engineered in my opinion and I would look to other brands, also the tubes did not hold up well either......

I've had good luck with both Nautica and Novurania over the years. As well as others.

And on the boat I will hopefully be taking command of starting this coming Tuesday, they have been towing a 22 foot Nautica for the passed year or so. And other than needing TLC, it looks to be in fine shape.

After having a Novurania with a Castaldi jet, it was so bad the Owner made us give it away, I think the Port Authority in Monaco still has it.

I've also had a Yamaha Jet dinghy and that lasted less than a month before the Owner got rid of it.

Just get a RIB with a 4-stroke outboard.

Please.

Fish

I agree, the jet's are horrible. The 14' Nautica jet was terrible. At slow speeds you were at 3,000-3,500 rpm's to do 6 or 7 knots and the smoke was horrible, the engine noise was so loud where you almost needed ear muffs, and you couldn't keep the thing going straight to save your life. I would never ever recommend a jet rib, for any purpose.

Not to mention the time I had to go swimming in winter to pull the plastic bag out of the intake grate. And I happened to be coming back from lunch and fully dressed.

The 4 stroke outboards are quiet, you can get in just as skinny of water with them. It's the only way to go.

Totally agree on the jets. What a waste.

I had a jetboat on a boat I had just started running that the yachts builder had added two skegs to the bottom of the jet tender. It turned out to act as guides to help the tender align on it's mounts.

Well, I was unaware of them the first time I tried the tender after fixing it's starter.
So I go for my first ride in it after fixing the starter with a Bahamain friend who had helped me track down a starter on Harbour Island where we were staying at the time.

All is well until I go to make a sharp turn at speed, instead of sliding a bit like a normal jetboat, this one, due to the skegs, turned literally like it was on rails and throws my friend ass over tea kettle right out of the boat.

Other than loosing his $300 perscription sunglasses, which I replaced, he was wet but alright. I only stayed in the boat because I had a death grip on the wheel.

The jetboat was sold shortly there after.

It's interesting, the mix of reviews on them.
It's almost like they are either blessed or possessed when they come out of the factory. I've heard the same thing about them outside of the forum. Some use them / love them / reliable as ever, and others burn, sink, or sell them within the first few months or most definitively in the first year (season).

Do you think it's the diesel / yanmar on them? or is it the pump that's the issue? I can't guess the yanmar is that bad. We have a couple of them in different applications. Perhaps the pairing of the two is the culprit?

It depends on usage. If the application you're using them in, that you're running around on plane all of the time, they're fine. If you ever have to use a jet tender at hull speeds for anything more then 10 or 20 minutes, you will never, and I mean never want to deal with one again. If you run them at 20mph+ 98% of the time such as in the Bahamas where you're running from island to island and then just slowing down to idle for 3 minutes to pull in to dock, you don't notice how bad they are at slow speed manueverability, noise, and the vibration and smell...... Remember with a jet, to do say 7 knots....... you're usually at 1/2 the RPM's you'd use at cruise and going nowhere speed wise........so the motor is revved up, underneath you're steering wheel usually.......and the noise radiates up, because you're not going fast enough to have the wind push it way behind you.

Think of being in a cigarette. If you're doing 50 mph, you don't even hear the noise in the boat with the open exhaust. Try sitting at the helm at the dock and revving it up to 3,000 rpm's in neutral and tell me how long you can stand it.

Besides, have you ever read a BAD magazine review on anything?

The whole point of a tender is for use in an anchorage or marina where manovering in tight spaces is a must. Getting the guests ashore safe and dry is pretty much all you can ask of it.

If you want to shoot off-shore for a dive or a fishing trip, now you need a new parameter of boat. Boston Whalers of old did this job but the new ones are too focused on one job to be an allrounder.

Go back to basics, there's a bloody big market out there.

So what I'm reading is that it's not so much pairing a diesel engine with a jet, but the maneuverability of the RIB's because of the characteristics of the boat as a whole. (along with the noise and smoke inherent to diesel engines)

I only ask because we have considered moving from an outboard to an inboard jet. However haven't made the move yet.

Tell him to get a diesel outboard. Yanmar even makes some. Not sure how hard it would be to import one.

Has he ever run a jetboat before?

Judy,

I'm trying to work out just why your client wants a Diesel Tender. Diesels work best when warmed up and run at a constant temp (a Mack truck) not popping into town (a Rabbit). A small gas engine will always win on a short journey.

The best diesel tender I ever saw was on a Square Rigger, it was clinker built and varnished, sounding proper (chug-chug-chug). I'm not sure this is the image your client requires.

NO, the entire problem is with the JET. Totally wrong form of propulsion for a tender's intended purpose with no added value. Not to mention you're cramming a diesel or other inboard engine in the middle of a tender, when you're looking for the most people and weight carrying capacity for it's length to start with. The 4 stroke outboards are so quiet and fuel efficient, why even worry about a diesel anyways in a tender?

Yes, I understand the issues with low speed control with a jet. Simply, it doesn't turn unless you are in the throttle. Essentially, a jet ski.

I think I have a pretty good grasp on the general consensus at this point from the discussion here.

Much thanks-

Weight

Another point being missed is the weight penalty of a diesel, which will require a much stronger davit, which is more weight, etc...

nas

Judy,
I echo many of the comments here. I've never owned a diesel jet tender but have many friends with them. The larger ones seem to be a little better, but the small ones are a nightmare. I'm a big fan of Nautica and have had many of them. Franco builds a good boat and, more importantly, stands behind his product.
My first advice would be to strongly advise against a diesel tender. While it may be cool to be able to fuel the tender from the main tanks, the hassle associated with small diesels may outweigh the benefits. Perhaps the 3500# davit could be utilized when lifting a gasoline tender with a larger than average fuel tank, therefore minimizing the need to carry extra gas in a storage tank.
If the client is set on a diesel, perhaps an Inboard/Outboard would be a better option than the jet.
Good luck.

Think you've hit the nail on the head there. No class issues with gasoline and pratting around with jerry cans.

I've had a dozen + diesel tenders with no problems, can't quite understand some of the posts here talking about diesels not being suitable for tenders. As for Nautica, dodgy quality at best but they are cheap (in every sense).

There is no problems having a diesel engine. But you are dealing with a tender that weighs more then equipped with a 4 stroke, aren't gaining anything in fuel economy, and it has less interior room for passangers and provisions which is the primary use of a tender.

I too would only go the stern drive route if possible with a diesel tender. BUT, that makes the tender weigh even more AND makes it longer then a jet equipped one of the same boat length.