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Old 20 November 2011, 01:54   #1
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First ride in Dockitjet

It only took a year but I finally got it in the water.

Dockitjet makes RIB's that have a cutout you dock your jetski into and use that as the means of propulsion. This particular one is a one off 5.6m aluminum hull that takes an outboard.

It was built for a dive company in NZ but they went broke before they took delivery, in fact it was before the boat was finished.

I purchased the bare hull (120kg's), added the console and finished the rigging with a 1996 200hp fuel injected 2 stroke Suzuki that we rebuilt. The 200 liter fuel tank doubles as the seat.

The trailer is mainly made of plastic which is great for rust prevention, not so great on really hot days in Sydney when it bends.

First run today and I quickly realised I have connected the hydraulic steering backwards so I need to steer opposite. This is not too bad when underway but quite difficult when docking and when chime walking.

I have fitted a 25 pitch prop to start and according the the iPhone gps can do 56 km/h at 3000 rpm. Couldn't get a read at higher speed as I realised Velcro will not hold the cushion in place and the seat falls off when there is chop.

At 4000 rpm it also starts to chime walk and that was just too hard to steer it out with the steering backwards.

And the best bit, it literally jumps out of the water when you hit the throttle.

All in all very happy, just need to sort out some teething issues.
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Old 20 November 2011, 03:38   #2
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Good for you! Enjoy the new Boat
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Old 20 November 2011, 06:51   #3
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Quote:
Originally Posted by kubcat View Post
First run today and I quickly realised I have connected the hydraulic steering backwards so I need to steer opposite. This is not too bad when underway but quite difficult when docking and when chime walking.
You're not the first one on here to do that! Name withheld to save the member's blushes.

That's a lot of horsies on a light boat

Enjoy
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Old 20 November 2011, 09:18   #4
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Quote:
Originally Posted by kubcat View Post
It only took a year but I finally got it in the water.

Dockitjet makes RIB's that have a cutout you dock your jetski into and use that as the means of propulsion. This particular one is a one off 5.6m aluminum hull that takes an outboard.

It was built for a dive company in NZ but they went broke before they took delivery, in fact it was before the boat was finished.

I purchased the bare hull (120kg's), added the console and finished the rigging with a 1996 200hp fuel injected 2 stroke Suzuki that we rebuilt. The 200 liter fuel tank doubles as the seat.

The trailer is mainly made of plastic which is great for rust prevention, not so great on really hot days in Sydney when it bends.

First run today and I quickly realised I have connected the hydraulic steering backwards so I need to steer opposite. This is not too bad when underway but quite difficult when docking and when chime walking.

I have fitted a 25 pitch prop to start and according the the iPhone gps can do 56 km/h at 3000 rpm. Couldn't get a read at higher speed as I realised Velcro will not hold the cushion in place and the seat falls off when there is chop.

At 4000 rpm it also starts to chime walk and that was just too hard to steer it out with the steering backwards.

And the best bit, it literally jumps out of the water when you hit the throttle.

All in all very happy, just need to sort out some teething issues.
Made the mistake of reading this whilst having lunch Nearly choked Best laugh I have had in ages, sorry, but a plastic trailer that bends and steering that is brain bending, I think you need to take a time out
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Old 20 November 2011, 15:12   #5
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I never thought I would ever say this but I think I have gone a little too big in the motor department.

Having said that the boat sits well in the water, the transom has not even the slightest hint of flex and all in all feels great. Probably need to add some weight forward to assist with the chime walking though.

And yes it was the strangest feeling coming off the trailer trying to figure out what was happening without hitting anyone else.
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Old 20 November 2011, 15:28   #6
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How high is the motor on the transom? You could try to raise it a bit.
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Old 20 November 2011, 20:31   #7
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We were pretty conservative with the engine height so we should be able to go up. I could trim it up a really long way without prop slip.

Do you think this will help with chime walking?
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Old 21 November 2011, 03:40   #8
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It did on a boat I had chine walking a couple of years ago....
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Old 21 November 2011, 06:29   #9
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Just did a Google and it seems agreed to work. Thanks for that.

Unfortunately I had another look at the transom and I only have room to go up one hole. My mechanic said I had a transom that was an inch or two shorter than normal. The cavitation plate is above the bottom of the V anyway, so maybe the height wasn't as conservative as I first thought.

I have a 3 blade prop on at the moment so may try one with 4 blades. Apparently this can also help sometimes.
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