Outboard permantly in Water? (sailor)

[Inselaffe]

Hello, someone on PBO reader to reader suggested here would give me a more informed answer!

It's not possible to remove my current outboard (9.9 4-stroke Yamaha 1995) from the cockpit well of my ETAP 22 sailing boat (1250kg, LWL 17'8'') without removing the prop (must be about 10-11" diam) so it will have to stay permanently in the saltwater (the previous owner had it in fresh water). There is absolutely no room to tilt it or anything.

There is no way the outboard will come out, there's no rubber gland, I already removed a home-made-bungy-held-in ally plate that was to stop water splashing up the edges of the leg. The well in the hull is just too small for the prop to come through, it'd mean a dive to take the prop off. I suppose no-one could nick the outboard though ! (but then I have to make sure that no-one could start it (manual start)). I'm pretty sure that even with the prop off that to get the anticavitation plate through I'll have to take out the mounting board that goes across the front of the well. Even then it'll be really tight, and the motor weighs 45 kg, that's 5kg less than me (I need to drink more beer!).

Will this rapidly corrode the outboard? will encrustation of the cooling inlets become a problem? Willl weed growth be a problem? Is this at all advisable to leave an outboard always in the water? Any other thoughts?

Another perhaps relevant point is that I will be on a half tide mooring onto mud, so problems with mud in water intakes/outlets?

Thanks for your attention!

Leigh
PS, By the way, is that an 'anticavitation' plate or an 'antiventilation' plate above the prop? Surely it'd only stop ventilation from the surface?


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[BarryH]

Theres not much difference betwixt your outboard and an outdrive found on loads of powerboats. The outdrives spend loads of time in the water if the boats kept on a mooring.
I would check the anodes though. Could even put a couple of extra ones on just to make sure.

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[Talbot]

Although my outboard is not permanently in the water, the lower part of the bracket is just on the waterline, so I have the same problem. This part of the bracket had an anode on it, but it was not doing its job. I have added a stainless plate to the end of the lower pivot bolt on the bracket and it is sized to be underwater at all times. I have mounted a 3" circular anode either side at the bottom of this plate, and have not had any more problems with corrosion. (there has been no problems with it snagging on anything, and even if it did, its design would deflect the rope downwards and away) Your main anode on an outboard is the little circular job on the bottom of the cavitation plate, and this normally has a fin pointing downwards. The anode is normally too small for the job, and the fin erodes fastest, it is also the most important part of the anode as it helps to direct the flow in the correct direction.

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[Kevin]

Hi

it shouldnt make much difference outboard or outdrive, some outboards use the old outdrive alpha 1 'leg'.

I always call it an anticavitation plate but i keep getting strongly told its antiventilation, my thoughts were that is stopped the boat cavitating(much the same job as the 'add-on' doel-fins etc, help stabilising the stern and aiding lift) but apparantly its more to do with the movement of the water around the prop so that there is no ventilation. i think personally they both make sense, but which is right im not sure

kevin