Single Outboard

[David M]

Originally Posted by Johnathon123

I am looking at a boat at the moment which will be our first cat.

A bloke who has given me a lot of really great advice is warning us away from it as it has a single non steerable engine (outboard). My thoughts are he is right since he has been right about most everything else.

We will probably spend a fair bit of time in the marina regions of NSW & QLD for the first few years. The purpose of this boat is to get our confidence up on a cat before buying something bigger in a few years.

So how big an issue is a single engine in your opinion? At the moment I am taking the advice and walking away (or at least speaking to the designer and factoring in a mod to the price) but what would you do?

This depends on the length of the boat. An outboard needs to stay in the water in order to work. As a boat gets longer in length, the stern pitches higher meaning an outboard is going to be in the water for less of the time in chop.

There comes a transition area with length with a displacement sailboat that having an outboard is not going to be practical....which I think is somewhere in the upper twenties.

Sailboats with their big rudders with a little way on can steer an outboard pointed ahead just fine. I have done it plenty of times.

[fla.sailor]

I have a single outboard (25 HP honda) cat (gemini 3200) that steers with my rudders and we have spun it around in lots of marinas. Wind and current always add a pucker factor, especially in tight quarters but to us it was about learning the cat. We also did 3 months in the bahamas where we took a slip on several occasions without issues.

Our 32' cat is much lighter than our 33' mono and I found that change more noticeable when docking - our cat does not carry any momentum.

Yes, I'd prefer a pdq with dual outboards for a more turning control and as a backup engine (hmmm, how many mono's have a back up engine?). With just a little practice you will learn how to best steer your cat.

CHeeRS!
-dennis

[Cheechako]

There are some great kicker motors made now, extra long shafts, power tilt, 12" props, and steering kits available. From my experience they push amazingly well even up to 30 ft boat. Two 4 stroke 10hp OB's and a Honda 2000si for charging and you'd be the quietest boat in the anchorage! Cats are difficult to manuever in wind even with inboard diesels though, and in most cases OB's will not be thrusting directly onto the rudders. Still, on a smaller cat the idea of two of these is enticing. You need to think through the whole package though... how to make electricity etc. Could cost as much as small diesels...

[smj]

Originally Posted by David M

This depends on the length of the boat. An outboard needs to stay in the water in order to work. As a boat gets longer in length, the stern pitches higher meaning an outboard is going to be in the water for less of the time in chop.

There comes a transition area with length with a displacement sailboat that having an outboard is not going to be practical....which I think is somewhere in the upper twenties.

Sailboats with their big rudders with a little way on can steer an outboard pointed ahead just fine. I have done it plenty of times.

The length of the boat has nothing to do with it it's were you place the outboard that is the key. To far aft and you will cavitate. To far forward and you would lose the steering benefit of twin outboards or a single outboard attached to your rudders.

[44'cruisingcat]

Originally Posted by Tropic Cat

Well, let's see.. The original poster told us he would be in an out of marinas for the next few years. He asked for an opinion of a single engine in that context. Under no circumstances would I consider a single engine to be 'better'. That was my response to him.

.

Some serious backpedalling going on there.... going from stating that no experienced cruiser would even CONSIDER a single outboard powered boat to now saying YOU wouldn't consider one TO BE BETTER...

But the fact is, I do know experienced cruisers who DO prefer their single outboard over a twin diesel setup. As it happens one had a single steerable outboard on a previous boat, and now has built one with a single non steerable outboard.

The advantages of better sailing ability due to lightness and being able to lift the prop and gearbox out of the water, the ease of maintenance, the lack of diesel stink through the boat, the fact that the propellor is always clean and barnacle free without having to constantly use expensive and innefective antifoul on it, the fact that they can ground their boat, the extreme shallow draught....

Like most choices, there are pros and cons.

Me, I prefer twin outboards. Frankly I wouldn't have diesels if you paid me.

[smj]

True the diesel may last longer than the outboard but for the price of a single Yanmar 10hp diesel plus sail drive I could probably buy 4 Yamaha 9.9 high thrust outboards. My guess is 4 outboards would outlive the diesel and be a hell of a lot less expensive to install.
The charging capabilities of the diesel are greater than the outboard but with the cost of solar and generators like the Honda 2000 you would be crazy to put wear and ear on your diesels to charge batteries

[44'cruisingcat]

Looks to me like it really comes down to the actual boat. If it's a boat THAT SAILS, outboards, either one or two of them are a viable option.

If it's a boat that has to motor most of the time then diesels might be a better choice.

[thinwater]

Originally Posted by smj

The length of the boat has nothing to do with it it's were you place the outboard that is the key. To far aft and you will cavitate. To far forward and you would lose the steering benefit of twin outboards or a single outboard attached to your rudders.

Regarding twins, a forward location has no effect on the steering value of twin outboards. The PDQs have engines quite far forward and can easily turn without forward motion. I do it every time I back into my slip.

I had a single outboard on my Stiletto, mounted just a bit forward of the transoms. It really did not cavitate even in terrible conditions, but that is in part do to a low mounting and because the Stilettos have wide transoms that do not pitch too much (the bows pitch something fierce). My only point is that cavitating or not is rather design specific, and I have heard perhaps too many general statements in this thread. The wise comments say you need to test drive the boat in tough conditions.

The test sails of both of my cats were in rough conditions (the POs wanted to cancel) and that was what sold them.

[smj]

Originally Posted by thinwater

Regarding twins, a forward location has no effect on the steering value of twin outboards. The PDQs have engines quite far forward and can easily turn without forward motion. I do it every time I back into my slip.

I had a single outboard on my Stiletto, mounted just a bit forward of the transoms. It really did not cavitate even in terrible conditions, but that is in part do to a low mounting and because the Stilettos have wide transoms that do not pitch too much (the bows pitch something fierce). My only point is that cavitating or not is rather design specific, and I have heard perhaps too many general statements in this thread. The wise comments say you need to test drive the boat in tough conditions.

The test sails of both of my cats were in rough conditions (the POs wanted to cancel) and that was what sold them.

Your absolutely right, brain fart on my part

[beiland]

Originally Posted by Talbot

Having spent over 20 years with a catamaran with a single (steerable) outboard, my comments are:

If you can't steer it, and don't have a thruster, forget it

if it is steerable, in light winds it is as manoeuvrable as twin engine cats

In strong winds, they can be a pain.

The biggest problem was never the manoeuvrability, but the lack of electrical power. If it has no alternative power source (wind.solar) then you have a problem.

Best thing about them,

1) Being able to lift the prop out of the water when sailing (especially good if something gets caught round the prop)
2) Being able to remove engine and take it home to the garage to work on in the winter if it needs a major overhaul.

I think you covered most of the bases Talbot

[Ian R]

I have a single 9.9 yamaha not steerable but could be,so far I haven't felt the need,I don't go into marinas often.This boat had a single diesel that I removed,the outboard is quieter cleaner and lighter.It is not a great motor boat so I sail mostly.Boat motors at 5.5 knots at 1.3 litres per hour and 6.8 knots wot in calm conditions.It's a 32 ft. cat.
Ian

[Johnathon123]

Hi everyone, thanks for the advice. As always a great place for advice on all levels.

Still looking so I will let you all know how we go. We are certainly getting closer, I can feel it. And THAT is a good feeling!