Stern Thruster

I am thinking of installing a stern-thruster (side-Power)
on my 37 Pacific Trawler. Anyone out there have this set-up. I assume it needs to be installed to starboard, off center. Will I need the cowlings?
Any clues on the most economical supplier. I am retired, on a fixed income so I need to nickel and dime this installation if I am going to be able to have one at all.
Open to all suggestions and or ideas. TNX

Someone posted in a recent thread they saw a 50lb thrust electric trolling motor mounted sideways below a swim platform being used as a stern thruster if cost is the primary concern.

Here is the Side-Power stern thruster as installed on my AT 34. It is centered and as low as possible. The eyebrows help keep the thrusted water directed below the water line to maximize thrust.

This stern thruster is connect along with the bow thruster to the engine start battery (AGM 4D). The controller is a boat shaped dual control for both bow and stern and is very intuitive and easy to use. Twist or push it in any direction and so goes the boat. It can be seen on the lower left of the helm.

This was done by a marina before I purchased the boat and cost $7,500. I don't have any parts/labor breakdown.

Very worthwhile addition to a single.

Why do you want one Stan?

I'm wondering if you want one for the same reason I'd like to have one.

We have a Side Power stern thruster on our Sea Ranger 47 which has twin Ford Lehman 135 engines. We also have a bow thruster.

We had the thruster toggles installed in both the pilothouse and our flybridge ... the thrusters were worth every penny!

There is a guy from Florida that lines up a bunch of work in Texas and then flies over and knocks it out. I have 2 close friends that just had him do a Bow Thruster on their boats for $6900!!! I thought that to be a screaming deal and his work looked absolutely top notch....includes separate battery and separate charger for said battery. Maybe he does this all over the country????

I am in the same position you are. Here are 3 External do-it-yourself kits that I found. All have their own advantages/disadvantages. I received quotes on all of them, so the pricing is up to date.

Cap Sante in Anacortes sells a "box Thruster" kit for about $4,200 with everything you need for the install

Yacht Thrusters out of Florida offers a kit (compact-stern or Bow) for $5,050.00 Both minimally invasive and pretty cool.

Side Shift Thrusters are the most economical and easiest to install. The cost is $3,600.00 from WMJMarine.com

Better learn to be good without them though...both bow and stern thrusters can be amazing and also make you become a thruster addict worse than any morphine habit!

psneeld said:

Better learn to be good without them though...both bow and stern thrusters can be amazing and also make you become a thruster addict worse than any morphine habit!

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It's a great safety addition. I don't care to be what others deem "good", nor do I intend to enter into any handling competitions. The debate over whether they're needed or not has been exhausted in other threads. Hopefully the research/pricing that I gathered helps answer some questions for those seeking it.

Adelaide said:

It's a great safety addition. I don't care to be what others deem "good" nor do I intend to enter into any handling competition. The debate over whether they're needed or not has been exhausted in other threads. Hopefully the research/pricing that I gathered helps answer some questions for those seeking it.

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As you posted...it could be vigorously argued whether they are safety related...but are very handy and the research I'm sure is greatly appreaciated!!!

If you had the choice between Hydraulic or electric Bow and or stern thruster.
which one would you choose and why.
SD

psneeld said:

Better learn to be good without them though...

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Good point. We've seen a fellow come into Nanaimo in BC in some sort of 45-50 foot cruiser and in the middle of maneuvering into a pretty tight spot on the dock his bow thruster quit. Lots of yelling and franticness with the throttles (yes, it was a twin) and after doing what appeared to be several thousand dollars worth of damage to his own and two other boats he got it nicely tied up.

skipperdude said:

If you had the choice between Hydraulic or electric Bow and or stern thruster.
which one would you choose and why.
SD

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Assuming the boat could be rigged with the proper equipment, hydraulic bow thruster.

Other than some very specific situations I don't see much value in a stern thruster since the prop(s) and rudder(s) already is (are) one. But moving the bow sideways without moving the stern the opposite direction can only be done with a bow thruster. Even though we have a twin and so far have had no significant problems getting the boat to do what we want it to do, a bow thruster would come in very handy at times. We've never found ourselves wishing we had a stern thruster.

And hydraulic because you can run them all day without tripping a breaker or overheating them Plus they don't make a noise like a can full of rocks being shaken not stirred. Granted, all but the dirt-cheap electric thrusters give you enough time before tripping the breaker to do whatever you need to do most of the time. But the noise is absolutely hideous.

And from comments I hear all the time from other boaters around us in the marina (most of whom are sailboaters) the sound of an electric bow thruster is like making an announcement that "I don't know how to maneuver my boat."

after doing what appeared to be several thousand dollars worth of damage to his own and two other boats he got it nicely tied up.


That cracked me up.

Funny stuff today or is it just me?

Sd

Hydraulic for sure now that I've been using mine (stern thruster) for 5 seasons. Many times I run it for more than just quick bursts like you have to do with an electric thruster.
One example is when I go into my slip (or a guest slip) and I need to pin the boat against a piling so I can leave the helm and secure a line. Very handy for that.
Also during anchoring to keep the boat properly into the wind. Sometimes it needs to stay on for extended periods.
The down side to hydraulic is that it runs off the engine and loads it down, bringing the idle very low when it's activated. Also it is not supposed to run at over 1000 engine rpm, so sometimes that gets to be a "hand management" problem with shifter, throttle, and thruster switch.

As to bow or stern, I think I would prefer to have a bow thruster. Sometimes there is too much wind and my fat a$$ trawler with the big keel don't like to move on over as well.

While renting Canal Trawlers in Europe, I got pretty spoiled on Hydraulics. Twice we rented one of the Euro 400's (I believe), and it had a hydraulic bow thruster and a Nanni Hydraulic Drive. You could pull the throttle right through the gate from full forward to full reverse with no worries. It was nice for doing full throttle Captain Ron style docking at the Locks (theoretically). Without a keel, these things really needed the hyd. bow thrusters, although they surely did announce your unskilled arrival. When exiting a lock, you had oncoming traffic, and sometimes there were some real surprises with cross winds.

If I end up doing anything Hydraulic, I'll probably do everything I can hydraulic. Windlass, boom, thrusters, and a get-home four-bolt transom mounted hydraulic motor and prop. There is at least one style of hyd. stern thruster over there that can double as a get-home option (if you're not to far from home and not in too much of a hurry). Anyone whose ever driven a forklift or bucket-loader knows that continuous use of hydraulics can produce a lot of heat, and I'd want a temperature sensor on any hydraulic motor used for get-home purposes.

My boat has a full keel and handles well in side winds, but I have contemplating extending the pilothouse, and part of that plan would include the addition of a stern thruster. If I had my choice of systems, it would be hydraulic.

"The down side to hydraulic is that it runs off the engine and loads it down, bringing the idle very low when it's activated"

This is the reason many folks will install the hyd pump on the noisemaker , or the "get home engine " if one is fitted.

FF

Prior to us buying our present boat, I use to scoff at people with thrusters and there over use. Our new boat came with both bow and stern. I can honestly say that it did not take long for me to convert my opinion. With the larger boat, greater sail area and a tight slip, it did not take long for me to fall in love with them. One side advantage was the Admirals comfort level when we dock went way up.

I have seen several boats equipment with the hydraulic systems and the emergency hydraulic drive on the shaft. I use to design hydraulic systems and heat is a factor as pointed out. Much heat is generated through the sizing, fittings and run of the system. Over sizing the run and minimizing bends and fittings will go a long way to reducing heat. Sufficient reservoir size is also a factor. But if you intend to run for long periods of time, such as in the case of the "Get home" system then running an oil cooler is the best way. Being on a boat a keel cooler or water cooled heat exchanger are the best methods.

Thruster noise

I have to agree with Marin on the noise of the thruster announcing my lack of skill at boat handling, especially since my last two boats have been twins. I have to admit with the current weight and draft of my Hatteras I really haven't missed the bow thruster I had on my 4788 Bayliner. And I don't think I will be adding one to it. The Bayliner however is light and even after placing it perfectly against the dock or centered in the slip the wind could blow it off the dock or side ways in the slip very quickly. The bow thruster got a lot of work centering and holding the 47 against the dock. I had the opportunity to work on a Albin trawler with a single Lehman and it had a stern thruster. Even though you can back a single using propwalk combined with forward right rudder to back fairly straight having the thruster made it much easier and quicker to back out of tight spots. The only hydraulic thruster I've used was on a 50' single with a single the thruster required me to increase the main engine RPM to produce enough thrust. So it limited how you used it, probably best to be out of gear when using the thruster, in this case. I found this awkward to say the least. This would argue for powering the hydraulic thruster off your genny, as most likely any engine rpm change would effect thruster output. I had an An American Bow Thruster on my 4788, I never never had a problem with it overheating or running out of battery.

Thanks for the response. Appreciated the pictures.

Thanks for the response. Americans
are built about 30 miles from me. Nice Boats, high quality construction.

My main reason for wanting a stern thruster is the added safety when docking in a side wind. In addition it may allow me to single hand boat which I wont do know.

Thanks for the response. I have looked at other thruster but prefer to stay with the side power to match my existing bow thruster. I will try Cap Sante for their package deal, as they are only 50 miles from where I'am located.

Thanks for taking the time to respond to my request. Prop walk is fine until I'm in a cross wind of more then 10 knots and then it gets exciting. Have a great summer.

I have found that in most cases sail boat respond much better to their rudder then power boats.In addition the deep keel helps resist side movement in a cross wind. My boat is a single screw and while I can prop walk it under most circumstances, when in a side wind of more than 10 knots it can get exciting at times. I see a stern thruster as being a safety device.

Marin,
For single screw guys I would think backing in winds or breezes not to mention current would be greatly enhanced w a stern thruster. I'd sure like one while backing down as I set up the anchor for a set. With the wind and current working on the boat backing can sometimes be impossible. I think the best solution is to set up your bow to be blown downwind and make sure you present the right (correct) side to the wind. One way works far better than the other. ie ... If you pull to stbd in reverse give the port side to the wind. The bow will go downwind and the stern prop walk should keep the stern going in the same direction so you wind up going a bit sideways but under control and get the job done w/o much cuss'in.

So I'd like to have a stern thruster but it ai'nt worth no $7000 to me.

manyboats said:

So I'd like to have a stern thruster but it ai'nt worth no $7000 to me.

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I'd feel the same way, but our boat came with one and, although seldom used, its nice to have it at times.

Dated thread, but I thought I'd add a bit. We finally installed a Lewmar stern thruster on the Albin A27. Single screw, huge keel (at least 6 or 7 times the size of the rudder) with little to no steerage when backing down. I back the boat into the slip on the intercoastal waterway here in Florida. That often means both a tidal current and a sea breeze.

While I would never discount the importance of skill and practice, I've had literally hundreds of opportunities to turn the rudder stop to stop with no directional change in the boat while backing down. Pre stern thruster, the solution on the Albin was to set the boat in the correct attitude going forward and then back down. The stern thruster has made our life so much easier and I am not ashamed to admit it (at least when running the Albin).

BTW... we did the installation ourselves and the total cost for the Lewmar 140TT was in the $2k range. The A27 is short (27') and light (6500 lbs) so a small thruster was sufficient.