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Old 03-11-2013, 11:36   #16
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Re: Externally Mounted Bow Thruster vs. Traditional Tunnel Type

Probably 75% of private owned sailboats in the Med have bow thrusters. It does rob you of some speed but I don't know what the actual numbers are.
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Old 03-11-2013, 12:09   #17
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Re: Externally Mounted Bow Thruster vs. Traditional Tunnel Type

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Originally Posted by robert sailor View Post
Probably 75% of private owned sailboats in the Med have bow thrusters. It does rob you of some speed but I don't know what the actual numbers are.
Their Yacht Thruster web site states it's slows you down only .05% compared to the 10% from a tunnel thruster.

Its about the same as a folding prop.
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Old 03-11-2013, 17:40   #18
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Re: Externally Mounted Bow Thruster vs. Traditional Tunnel Type

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Do a little searching here on the forum, and I think you'll find most people would think their predicted 10% loss of efficiency for a tunnel thruster is way too high. That said, I wouldn't put either on a sail boat. A proper installation does make all the difference, though.


That looks pretty efficient looking and would certainly brake most of the vortex. Thanks for posting the picture. Something like that I would consider, if I were looking.

One could always put in a small bow rudder.

Docking info
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Old 03-11-2013, 20:19   #19
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Re: Externally Mounted Bow Thruster vs. Traditional Tunnel Type

Sorry, but I can't resist!

Bow Thrusters, US Navy Approved:
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Old 03-11-2013, 20:38   #20
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Re: Externally Mounted Bow Thruster vs. Traditional Tunnel Type

Is there any support for that 10% loss of speed with a tunnel bow thruster??
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Old 03-11-2013, 21:10   #21
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Re: Externally Mounted Bow Thruster vs. Traditional Tunnel Type

Learn to use spring lines and ya won't need a bow or stern thrusters near as much !! LOL
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Old 03-11-2013, 21:13   #22
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Re: Externally Mounted Bow Thruster vs. Traditional Tunnel Type

Won't do you much good when you are Med mooring
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Old 03-11-2013, 21:14   #23
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Re: Externally Mounted Bow Thruster vs. Traditional Tunnel Type

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Originally Posted by robert sailor View Post
Is there any support for that 10% loss of speed with a tunnel bow thruster??



No! Much as I've been the thruster on sailboats detractor around here, I think that number is madness on anything but the most inept installation. Maybe if you put an 11" tube in a 20' boat with no fairing.
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Old 03-11-2013, 21:19   #24
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Re: Externally Mounted Bow Thruster vs. Traditional Tunnel Type

I've never had any use for them myself but here in the Med in a cross wind its a very nice thing to have. Lots of banged up boats here without them.
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Old 04-11-2013, 02:53   #25
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Re: Externally Mounted Bow Thruster vs. Traditional Tunnel Type

While they certainly have uses, learn to handle the boat without it and then use it as a backup if you get in a bad situation.

I've seen a few of boats with thrusters grinding away smash into docks hard when the thruster didn't have enough power. In all cases, there were easy options to avoid the issue with the standard controls but they appeared dependent on the thruster.
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Old 08-11-2013, 18:05   #26
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I have a 44 foot trawler (Gulfstar) and am looking to add a bow thruster. A company by the name of Yacht Thruster (a sister company to Side Power) has both a traditional tunnel type of thruster plus a new (3 years now) bow externally mounted model (e Thrust). I am at the Ft. Lauderdale boat show and at the Yacht Thruster booth, they strongly recommend the bow externally mounted model. Advantages (according to company personnel) for externally mounted bow thruster - water cooled so can run much longer, takes less amperage and because mounted further forward on hull, much more effective thrust. Does anyone have any experience with both internal and external bow thrusters? Which one do you recommend. Other than perhaps an "add on" visually distracting appearance when the boat is up and running, I am tending to favor the externally mounted model. Any help or guidance would be appreciated. This is my first post as a new member to the Cruiser's Forum and I am anxious to learn the results of my post. Thanks from CampbellsSloop.
Campbellsloop if you want to see an external mount there is one on a 40' Catalina at CIC marina south. I know the owner and can put you in touch if you want to ask any questions. I have a tunnel mount on my Beneteau 423 and swear by it especially docking in strong winds.
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Old 08-11-2013, 18:19   #27
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Re: Externally Mounted Bow Thruster vs. Traditional Tunnel Type

My stern thruster:



My non-protruding bow thruster:



(Main propulsion is with a single propeller.)
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Old 09-11-2013, 05:50   #28
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Re: Externally Mounted Bow Thruster vs. Traditional Tunnel Type

I appreciate all of the replies but still have not heard from anyone who has experience with both an internally mounted tunnel type bow thruster and also externally mounted Yacht Thruster type of bow thruster.
For those of you who do not believe that bow thrusters are necessary, ask a boater who has had a boat without bow thrusters and (same person) has also had a boat with bow thrusters. I believe you will find that bow thrusters are tremendously helpful and even critically needed in some windy circumstances. A Florida broker friend told me that I would find bow thrusters so handy that I would wonder how I ever got along without them. (sort of like a cell phone) Up to this point I have always thought bow thrusters to be sissy. However, now that our 44 foot trawler is in a double slip (with a half million dollar boat beside me) on windy Lake Erie, I believe they could add to peace of mind when coming into my slip on a windy day or be extremely helpful in getting away from a dock where I am pinned by the wind.
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Old 09-11-2013, 07:25   #29
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Re: Externally Mounted Bow Thruster vs. Traditional Tunnel Type

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Originally Posted by CampbellsSloop View Post
. A Florida broker friend told me that I would find bow thrusters so handy that I would wonder how I ever got along without them.
EDIT: CSloop, this is not directed at you, but rather a rant in general about people who run boats in excess of their ability, and the gizmos that let them do it

Well there you go; FLORIDA: the home of the single largest group of inept boat operators in the world!

I have spent the last 35 years on the Florida waterfront. I spent about ten years in the assistance towing business, and can tell you first hand that about 1% of the people plying the waters here have the slightest clue about what they are doing. The other 99% feel that if they have the juice to write the check, they MUST be able to drive the boat perfectly right out of the box! Cute gizmos like thrusters and chart plotters allow the inept to get by….. to some extent… but they all eventually wind up at the end of a towline or in the paint booth. They even have computer-controlled self docking boats for fenders’ sakes!

I’ll go along with the “convenient” argument, as I have an aux diesel in my sailboat… It IS convenient, no doubt, but then again I can do just fine without it. Before someone says it’s because my boat is only 28’.. I have on many occasions sailed much larger vessels (65’+) on to the slip after the aux has gone on vacation. Oh, and back to bow thrusters, I ran push boats with two 110’x50’ head barges up and down the ICW……270’ total….. with no bow thruster and never hit a thing.

So to get back on topic, scrap the idea, expense, loss of performance, and maintenance of a thruster (of any kind), and expand your training and experience. Or admit it is a shortcoming of the operator’s ability and not a “need”.
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Old 09-11-2013, 08:34   #30
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Re: Externally Mounted Bow Thruster vs. Traditional Tunnel Type

Thank you Capt Capngeo. I do appreciate your opinion but I also respectfully disagree with your conclusion. Nowhere do you say that you have driven a boat with bow thrusters. So, I am guessing that you have no idea as to how helpful they can be. In reference to my opinion, I am 71 and heve been boating for 50 years. This is my fourth twin engine boat. I have cruised the entire Loop, another one half of the Loop and have boated roughly twenty thousand miles. The fact is that wind does not push around a sail boat (unless sails are up) going into a slip as it does a two story power boat. In addition, I have witnessed many Great Lakes sail boaters lose control during docking strictly do to wind speed and direction (and not because of their boating abilities). You can tout no bow thrusters all you want but (for instance) as in driving a car, do you have power steering on your car? No one needs power steering either, but it sure comes in handy in simple everyday driving. Same with 4-wheel drive - if you need it, it sure is helpful. And lastly, my Florida broker friend also has a captain's license and mostly runs 50 to 90 footers - so I do respect his opinion. In conclusion, I am truly pleased that you responded, but I am beyond the question of whether or not bow thrusters are needed by me.
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