Bow thruster - is it a plus or minus?

kappykaplan · May 3, 2020

In my opinion, a 32-ft sailboat does not need a bow thruster. I'd see it as a negative for this boat. :beer:

TomY · May 3, 2020

A bow thruster in 32'? Hmmm,....

My only input for you is that this boat, a custom design and build, had a bow thruster. It had everything so $$$ was of little concern. But I was told the boat was not very maneuverable under power. It was very shoal draft and only drew 2'6" with the board up. The draft was crucial for an owner who's waterfront was shoal.

See the underbody? No keel stub and the dual rudders get no prop wash.

But it's a sailboat that sails like a dream!

And think of you pushing that button the docks, Scott (not sure which one though,...).

sail sfbay · May 3, 2020

On a smaller boat like a Catalina 320 you probably do not need a bow thruster BUT it will come in handy to dock when the wind is blowing you off the dock and when undocking a boat with the wind pinning you on the dock. They are very common on larger sailboats. I have one on my Hunter 46 and use it to center the boat when backing into and out of the slip. Once I am clear of my slip I use to make a sharp turn into the main marina fairway and avoid a large expensive powerboat downwind of my slip. I then use it when lining the boat up the slip prior to backing in, especially with wind.

Let us know what you decide and if you purchase the Catalina with a bow thruster what your experience is with it.

Sailm8 · May 3, 2020

Another maintenance item and for sure an extra battery and all that entails. I agree a 32 is too small for a thruster.

sail sfbay · May 3, 2020

Sailm8 said:
Another maintenance item and for sure an extra battery and all that entails......

You are correct that there is the potential for added maintenance (see link). Fortunately have not had any maintenance on a 15 year boat other than zinc inspection every 3 months during bottom cleaning and out of the water inspection every 3 years when bottom painting. It did not require an additional battery. Would not add one to a boat if one was not installed originally due the cost. Even my 56 ft Spindrift Motor Yacht did not have one and I never found a need.

Bow Thruster Maintenance

Proper bow thruster maintenance will ensure the best performance from your bow thruster Bow thrusters are part of what I

southernboating.com

SycloneDriver · May 3, 2020

I took a 2008 Beneteau 31 out for a trial yesterday. It's docked in a tight spot but I didn't really think much about it, until I turned the wheel backing out. My 1988 Beneteau F285 backed great but not this boat. Even while motoring forward the helm is not very responsive. I'll just have to get used to it.

Scott, if you have plenty of room to maneuver, the bow thruster is a negative. Maybe the previous owner didn't have room to safely get in and out of his slip.

smokey73 · May 3, 2020

I'd say it is a "wash" for you. If you don't need it and the rest of the boat appeals to you as to condition and price go for it. If installed correctly and there is no evidence of leakage I'd keep it as long as it works and then when it no longer works or needs major repair I'd just "let it go" and on the next haul out consider glassing over the tunnel. If you find you like it or need it then you can reconsider that and do the repairs. I would not use it solely as a basis to buy or not buy unless you know there are problems with it. I would imagine it might slow you down a little when sailing since it interrupts the smooth flow at the bow so if you're considering racing I'd ask for an allowance to fiberglass over the tunnels but you'll probably get some funny looks on that since it is an expensive upgrade. How does the rest of the boat compare to the others you are looking at? That is the bigger question.

BigEasy · May 3, 2020

Is a thruster necessary on a 32 foot boat; absolutely not. However, I would not consider it a negative; consider the thruster a luxury item! You're absolutely correct that an owner is not going to discount the price of the boat because you consider it a negative; after all, would you consider discounting the price after spending thousands to have one installed...not likely. Would you consider a windlass on a 32 foot boat a negative even though there is potential for mechanical or electrical problems? What about a generator or radar? You probably wouldn't reject a boat because it has one of these non essential accessories that may cause problems in the future. So, if you like the boat and it is your first choice as compared to other boats, you're satisfied with the price, location, and everything checks out on survey, buy it.

Don S/V ILLusion · May 3, 2020

A bow thruster is a nice accessory which can be useful in some situations, however, some are dependent on it which can be a problem.

jssailem · May 3, 2020

Just an opinion. 32 ft boat. Bow thruster is an expensive add on. Like a “self driving - parking” car. It is only money. Both to purchase and to maintain.

I do everything a bow thruster would do but with spring lines and prop walk. My boat is 35 ft and has more freeboard than a Catalina.

A hole in the bow to position a thruster just has to affect the sailing qualities of a boat.

Sure on days when the wind is howling and I am maneuvering in a tight space, I will have to make more than one pass and perhaps back in rather than bow first. But I am in no real hurry to swing in fire up a thruster and snug the boat in sideways between to yachts. Nor do I want to maintain the additional power demands. A windlass is enough of a battery hog.

Now if I was on a 55 ft boat and trying to slip into tight spots at a marina solo sailing. Well I would give a thruster consideration.

It will be your boat and your choice.

jon hansen · May 3, 2020

life is choices, you a sailor or a motorsailor?

dlochner · May 3, 2020

A bow thruster on a 32 foot boat isn't essential. The big hole in the front of the boat will affect sailing performance, which may or may not be an issue for you. There will be turbulent water around the hole which will disturb the water flow along the hull.

When I put my old school hat on, I say no to the bow thruster. Learn to maneuver the larger boat using the rudder and engine. Except for the momentum of a heavier boat, it shouldn't be much different from docking your 27.

When I put my old school slacker hat on, sure, its a great thing, don't have to work as hard or develop the skills to dock my boat under power.

Either way, I wouldn't pay extra for it and I wouldn't expect a discount for it.

dlochner · May 3, 2020

Scott, you ain't getting younger and your back isn't getting stronger. An electric windlass is much more important and useful than a bow thruster.

There may or may not be a dedicated battery for either the windlass or thruster. When there is a dedicated battery, it used as a buffer and the charging cable is much lighter. A thruster or windlass will probably need 1/0 or 2/0 cable to power it from the house bank. A dedicated battery near the bow will only need maybe 8 ga wire to recharge the battery. Cheaper and easier to run. The battery capacity isn't really an issue as the motor should be running when using either the windlass or thruster.

The hole in the bow will disturb the laminar flow along the hull and that will affect sailing. How much I can't really answer. It is also a nice home for those salt and brackish water critters that like to homestead on boats.

SycloneDriver · May 3, 2020

I really cannot comment on how much it affects sailing performance, I have no experience. I was thinking mostly about weight and maintenance when I said it was a negative.

jssailem · May 3, 2020

So that is the essence of my question. Why is a negative? My only concern would be sailing performance. I know I don't need it. That's not my question. My question is ... does the sailing performance suffer enough to lose interest in the boat or am I just being silly about considering it a negative?

Only reason for it to be negative is if you consider it a negative. If sailing performance (i.e. racing against other boats with out a thruster hole) is the issue then at thruster hole will be a negative. You will need to be smarter and work harder then your competition.

It's on the boat, I know (or think I know) that I can't get rid of it. Is it feasible to cover the holes? I've noticed that higher-end sailboats actually build in a retractable cover for the holes.

Yes you could build a plug to install or remove. Will it be a drag on your sleek hull? Yes. How much? Only you could tell by testing it. If a 3 bladed prop is a drag compared to a folding prop, then a hole in the bow will be a drag compared to no hole.

I'm not worried about battery maintenance. If I don't use it, I don't need a battery for it. However, this boat, and all others that we look at come with an electric windlass. Is it reasonable to assume that there is a battery dedicated to the windlass, and possibly the same battery would power the bow thruster?

This would depend on how the system was set up. I designed my windlass to operate off the main bank. I ran large lines from the bank to the windlass. The main batteries are near the center of the boat and low. No large bank needed near the bow to affect the balance of the boat.

Going back to the thruster, I don't like the hole in the bow. Does that affect sailing performance? Or am I being over-concerned about it's affect? Is it like dragging a dinghy or something I would never notice?

Without position and size dimensions there is no way to estimate the effect on sailing performance. What impact does dragging a dinghy cause? 0.5 knots - 1 knot? Do you notice that or do you accept it?

I have a friend who races his Cal 31. It came with a forward facing sonar. The bulge under the bow bothered him enough to remove the sonar system. No longer will the system tell him he is headed towards a rock. Now he adapts like the rest of us and looks at the charts before wandering into an unknown bay.

capta · May 3, 2020

There are very few boats under 85 feet that would require a bow thruster. In fact, IMO they are pretty dangerous as the owners come to rely on them and forget how to handle their boat without it. Then, when you really need it, it stops working and you have a problem. Not having a bow thruster keeps your boat handling skills in tippy top condition.
I was told by a marine electronics tech I really respect that the average lifespan of one of those small bow thrusters is only around 100 hours. Start using it for anchoring and when it is not really needed and you'd be surprised how fast 100 hours comes along.
I've been told, though I have no personal experience with this, that if imptoperly placed forward, they can really make the boat very wet going to weather, especially in a bit of chop.

Dalliance · May 3, 2020

Scott T-Bird said:
So that is the essence of my question. Why is a negative? My only concern would be sailing performance. I know I don't need it. That's not my question. My question is ... does the sailing performance suffer enough to lose interest in the boat or am I just being silly about considering it a negative? It's on the boat, I know (or think I know) that I can't get rid of it. I'm not worried about battery maintenance. If I don't use it, I don't need a battery for it. However, this boat, and all others that we look at come with an electric windlass. Is it reasonable to assume that there is a battery dedicated to the windlass, and possibly the same battery would power the bow thruster? Going back to the thruster, I don't like the hole in the bow. Does that affect sailing performance? Or am I being over-concerned about it's affect? Is it like dragging a dinghy or something I would never notice? Is it feasible to cover the holes? I've noticed that higher-end sailboats actually build in a retractable cover for the holes.

I’ve seen You-Tube videos where they added a bow thruster to an existing boat. Seems to me that you could also remove one and glass in the holes. Big project, but do-able. It’s not a necessity on a 32ft boat, but it may occasionally be nice to have if you are docking in tight quarters or with a cross wind. As for sailing performance, it’s completely counter-intuitive to me to put a tube through the bow. It has to have a negative impact and I would think it would be more pronounced on a 32 footer than it would be on a 40+ footer. Then again if you’re not racing and you otherwise like the boat, maybe it’s worth trying with the knowledge that you might want to make a modification and you factor that cost into your offer.

BigEasy · May 3, 2020

Scott T-Bird said:
However, this boat, and all others that we look at come with an electric windlass. Is it reasonable to assume that there is a battery dedicated to the windlass, and possibly the same battery would power the bow thruster? Going back to the thruster, I don't like the hole in the bow. Is it feasible to cover the holes?

Scott,
Most production boats that have a factory installed windlass use the house + starter banks to power the windlass, with the engine running, while you're using the windlass. As DL mentioned, there is a 1/0 or 2/0 cable that runs from the battery banks to the windlass thru a 75-90 amp breaker. That's how I installed mine after inspecting a similar installation on another Beneteau. Likely the same for a thruster. Having said that, there are others who have post production units that have a dedicated battery in the forepeak. If you feel that the negatives of a thruster are a problem for you, I would seriously look at other similar boats in your region before surveying this boat with the thruster. I would guestimate $1500 to $2000 for a yard to remove the thruster & re-glass the tunnel , barrier coat, etc. And, you have to have to ask yourself, do you want two large patches on your new to you boat?

Bow thruster - is it a plus or minus?

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SBO Weather and Forecasting Forum Jim & John

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SBO Weather and Forecasting Forum Jim & John

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