AUX Outboard on a Rib

[Pablo]

Firstly, I'm sorry for digging out an old thread but I asking myself the question if I will need an auxilary engine.

One thing i've noticed when reading through these post, yes i've read them all, is that several talk about using the aux engine to keep them off the rocks. Nobody seems to mention using an anchor to stay out of trouble, gain time, and try & fix the problem. Granted, the anchor will not get anybody home but it can help avoid complications.

[K&S]

Thanks for digging this thread up again Pablo gives me an excusse to ask the question what do people use / advise for a 6.5 m xs.

I was thinking i could mount an aux bracket on the transom with an aux mounted on it. The boat is 1.6m internal width with a suzuki 175hp on the back. I dont have the boat at the moment otherwise i could go do some measuring to see if it would work but with the boat show loaming i recon this might be the best time to get a discount.
Is there anybody that could advise if this would work and also which hp would be most suitable? I have been looking at the suzuki 9.9hp any thoughts?

[spartacus]

Interesting thread. I've had my Zodiac 7-Man Pro for over a year now. It's powered by a 2-stroke Yamaha 40hp Autolube which is perfect for cruising and fishing with 3 people on board in Moray Firth (NE Scotland). We usually hug the coast or venture 2-3 miles offshore.

Been caught off-guard once before with a force 6/7 but the boat performed well. However if the engine had been swamped or had developed fault we'd have been in trouble.

I'm seriously considering fitting an auxilliary engine this year for piece of mind, because let's face it, using Zodiac paddles just isn't an option. I have flares, GPS, compass, fire-extinguisher, and an anchor for back-up. Although I service the engine myself and I'm meticulous about regular maintenace intervals, engines can still fail.

I've seen one other 7-man Pro with a custom-built auxilliary transom bracket with a Tohatsu 2.5hp. See attached.

My boat is the one moored offshore (west coast of Lewis).

I'm considering a 2-stroke Tohatsu 3.5hp long-shaft becuase space is a premium.

Any thoughts?

[Pete7]

Originally Posted by K&S

Thanks for digging this thread up again Pablo gives me an excusse to ask the question what do people use / advise for a 6.5 m xs.

Some thoughts, I think the big problem is getting the aux prop down below the transom so the prop can work in clear water not hidden by the transom and if you are driving into the waves it stops the prop getting to close to the surface and ventilating as the wave rolls under your rib. However when I have tried long shaft engines mounted on the transom the prop drags in the water because it won't tilt far enough. So you then end up fitting a bracket for the engine, only look at the way they shake with an aux mounted on them when driven at speed doesn't inspire confidence regardless of what the manufacturer rated them at. 9.9hp should be fine (5hp worked well on a 5.95m with the prop well down and achieved 5 knots) its also just about portable. Andy has mine on loan at the moment but its to short for his Opsrey Viper transom. Also worth thinking about is that a yacht with an aux engine is quite a streamlined shape designed to travel easily through the water at displacement speeds. A rib at displacement speeds is anything but streamlined and has a huge drag effect from the flat transom which your aux has to overcome.

Pete