Single vs. Twin

[Everett1rob]

Apology accepted. There are some circumstances that no amount of skill will assure that you will not eventually damage your boat without the best setup of equipment. Every ones situation is different. My situation is having a 41' motor yacht that is 14' wide that I have to back into a 16' wide slip in a narrow corridor only 60' wide. So it becomes a challenge especially in rough water to pull into the corridor pivot my boat around 90 degrees with only 19' extra space and get it into a slip that's only 2' wider than the boat. Hence my desire for thrusters. Also I have chartered up to 52' monohull sailboats and no matter what your skill level the charter company has there on site staff take you out of the marina and meet you at the end of the week to bring it back in. There are not a lot of people with the skill to maneuver a large boat with one screw in tight areas. It is something you need to do consistently to be proficient at it. Even then I could see the tension on the face of the charter captain when he was bringing it in. Boats aren't cheap and it takes seconds to do a lot of damage or worse damage someone else's boat with yours! My comment about everyone I know that has a single gets frustrated are people with 25' and up cruisers. My personal opinion is that under 25' you shouldn't need a twin.

[Jaywalker]

There was always a lot of tension on my face, as well, every time I docked my small, no-engine, sailboat. I presume single-engine boats have something similar to my "dropping the sail at just the right time to allow enough energy to meet the dock at lower than destruction velocity." Yes, it does concern me, and I've been looking at thruster retrofit costs, but that's another thread.

[Irish rambler]

Take lessons ! it's actually quite simple once you learn. Some people are too proud to say 'Will you teach me please', maybe it's a macho thing.
I've taught many people and they all now have pride in their ability and confidence to tackle any situation, including making a decision to abort due to wind or weather, the secret is to know your boat and work with nature.

[Lancerbye]

Not all shoes fit all feet. If the marinas were all well thought out and engineered there would be no cross winds, no nasty currents, and adequate swing room.The marina I am presently at offers a lot of challenges to boaters who don't have very strong control systems. I have helped a lot of very good skippers come into their slips. When you have 45 ft slips on one side of the corridor, 55 ft slips on the opposite side and only 48 ft. for the corridor with slips having a natural cross wind and a strong current at times running in the same direction as the slip, docking is more of a challenge of timing and knowing your conditions at that time. You have to know how to read the water as well as the wind. Experience counts for more than training.

[Group9]

I've had lots of singles and one twin (inboards). The twin was the easiest boat to dock in the world because of having two engines.

But, it also meant twin fuel costs and twin maintainence. And, I did have one engine blow a head gasket sixty miles from home once, and it was nice to know I still had one engine left.

But, I have a 42 foot sailboat with a single inboard now and most of the time, it's pretty easy to dock (although there have been a couple of days with wind/current issues, when I was wishing I was in my twin powerboat).

My vote:

Easy handling, and rendundancy, twins win big.
Economy, single wins big.

But, there is a reason they made so many boats, both ways. Opinions vary.

[Delfin]

Different strokes for different folks, I suppose, but the setup on Delfin might work for some. Hydraulic bow and stern thrusters makes it possible to go sideways, pin the vessel against the dock when line handling by myself, pivot in her length, etc. The single wheel is very well protected by the keel, which is one of the main advantages of single screw. The cost of installing the stern thruster was less than installing a wing engine. Her mast makes it possible to carry a get home downwind sail that would get us someplace. Downwind, that is. The genset supplies the extra flow for the hydraulics, and is used frequently enough that it is easier to maintain than a wing engine. This clearly wouldn't work for most, but it does for us.

[eyschulman]

Jaywalker continue your process of inquiry and enlightenment as you are doing. read articles ,ask questions. There is only that anwer that will give you ccomfort. You will find conflicting opions witth a wide spread of anicdotal support. There is no right or wrong or better in this issue. I am nearing compleation of a two year custom buiild. Even though I had 50+ years of power and sail experiennce I spent a year researching drive sytems. It is not always an easy choice unless it is a used boat or production boat and the choices are limeted.My final choice was bassed on how and where I will use the boat and my general comfort zone with the drive choices avialable..

[chrisjs]

Many single screw power vessels have a back-up or "wing" engine for emergencies or "get-home' engine. We have a 56HP Yanmar coupled to a Yanmar SD50 saildrive with folding prop., located forward and off to port of the main propshaft. This is a totally redundant system with its own fuel filter, starter battery etc. We just run a few hours each year to make sure it will start!! Another approach is to have a separate engine driving an off-center regular propshaft and small secondary propeller. There does seem to have been a move towards driving the main gear via a hydraulic PTO from the generator of late, though this still uses the same main prop and does not provide the same level of redundancy. Of course if you have "back-up" sails as many of my sailboater friends do, you do not need to care about the engine redundancy, though it does seem as though they motor at least as much or more than they "sail"!!!!!

[Richard_W]

Originally Posted by Jaywalker

There was always a lot of tension on my face, as well, every time I docked my small, no-engine, sailboat. I presume single-engine boats have something similar to my "dropping the sail at just the right time to allow enough energy to meet the dock at lower than destruction velocity." Yes, it does concern me, and I've been looking at thruster retrofit costs, but that's another thread.

I've looked into this and the bow thruster cost is approx $3-4k diy, or $5-6k installed.

FWIW ... my boat is single engine sterndrive, without a bow thruster. We did a lot of cruising in the last two years visiting many unfamiliar marinas. After having trouble backing into the various slips and docks, I know my next boat will have TWIN ENGINES OR BOW THRUSTER OR BOTH.

I used to be able to dock a small trainer 22-30' sloop or ketch sailboats anywhere while single-handed. When we got this small 29' express cruiser I knew I will have to learn some and practice a lot. So, I did … and still after two years I have issues docking our new to us boat in certain wind conditions.

At first it was expected … I thought that I did not have enough experience and feel for the boat to back it into the close quarters nicely … but the situation has not gotten much better last year.

Frustrated, I took her into a protected open space harbor, no waves nor current, just wind, and tested how my boat reacts to wind in powerless drift, and while under power in reverse. Surprise, the boat's natural drift position is 30-40 degree into the wind (close hauled) and not into the wind (in irons) as one would hope a well designed (sail)boat would.

Furthermore, the idle power in reverse cannot overcome the force exerted on bow by wind stronger than 5 knots ... it is not possible for this boat to turn into the 5 knot wind while idling in reverse. This effectively makes docking in reverse impossible in windy conditions without pulling the throttle a bit harder which is a risky thing to do in close quarters ... and forget about backing while facing the wind, the boat will swing from one tack to another once the bow crosses the wind faster than I can think "oops … ."

This boat behaves like a weather vane facing the wind wrong way. The reason is a fancy looking hull design with high bow with deep concave walls that act like well trimmed sails ready for close hauled action. Another side effect of this design is that the boat will not stay put on anchor in light to moderate wind conditions. It constantly swings 40 degrees to either side.

Go figure!

[H Romberg]

Twins rock! I just got my first twin engine boat and I effing love it.

[Group9]

Originally Posted by H Romberg

Twins rock! I just got my first twin engine boat and I effing love it.

When I piloted my first twin (a 43 footer company boat), I was told to just use the transmissions and think of myself as driving a bulldozer with the gearshift levers. I did, and couldn't believe how easy it was to walk a 43 foot boat into it's slip, stern first, my first try.

[Cheechako]

Tough choice. When I have gone from sail to power I went single. Then I lived in fear of the engine quitting! I'm just more comfortable with a sailboat for that reason. However, the dual engine setup uses more fuel and doubles your engine maintenance. I've had no more real docking issues with a single engine trawler than a sailboat, but can see where I could have if I wasnt thinking ahead real well.

[markpierce]

How often do you see automobiles with more than one engine? Or freight ships (freighters), for instance?

[eyschulman]

This post is poorly directed. There is no better here, there is different with strong and weak points as there is with sailboat vs power boat. The choice often comes down to personal preference. Drive trains should be chosen as with boats bassed on there owner use and needs or often fanasy. Is an SUV better than a van or a sedan better than a sports car? It all depends on where you are comeing from and intending to go with what in the vehicle.

[Graceunderway]

Originally Posted by Richard_W

I've looked into this and the bow thruster cost is approx $3-4k diy, or $5-6k installed.

FWIW ... my boat is single engine sterndrive, without a bow thruster. We did a lot of cruising in the last two years visiting many unfamiliar marinas. After having trouble backing into the various slips and docks, I know my next boat will have TWIN ENGINES OR BOW THRUSTER OR BOTH.

I used to be able to dock a small trainer 22-30' sloop or ketch sailboats anywhere while single-handed. When we got this small 29' express cruiser I knew I will have to learn some and practice a lot. So, I did … and still after two years I have issues docking our new to us boat in certain wind conditions.

At first it was expected … I thought that I did not have enough experience and feel for the boat to back it into the close quarters nicely … but the situation has not gotten much better last year.

Frustrated, I took her into a protected open space harbor, no waves nor current, just wind, and tested how my boat reacts to wind in powerless drift, and while under power in reverse. Surprise, the boat's natural drift position is 30-40 degree into the wind (close hauled) and not into the wind (in irons) as one would hope a well designed (sail)boat would.

Furthermore, the idle power in reverse cannot overcome the force exerted on bow by wind stronger than 5 knots ... it is not possible for this boat to turn into the 5 knot wind while idling in reverse. This effectively makes docking in reverse impossible in windy conditions without pulling the throttle a bit harder which is a risky thing to do in close quarters ... and forget about backing while facing the wind, the boat will swing from one tack to another once the bow crosses the wind faster than I can think "oops … ."

This boat behaves like a weather vane facing the wind wrong way. The reason is a fancy looking hull design with high bow with deep concave walls that act like well trimmed sails ready for close hauled action. Another side effect of this design is that the boat will not stay put on anchor in light to moderate wind conditions. It constantly swings 40 degrees to either side.

Go figure!

We have single engine (CAT) and heavy 45 foot wooden boat. After two years, we also still have issues docking in unknown marinas and close quarters. I believe that our next boat will be twin engines. It is just safer and easier to handle.