Stern thruster recommendation

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Unclematt

Senior Member
Joined
Apr 9, 2020
Messages
324
Location
United States
Vessel Name
Seaview
Vessel Make
Sundowner 32
I am planning to add a stern thruster over the winter. What do you guys use, like and recommend. It is for the 32' boat in my avatar weighs 18,000 - 20,000 lbs. Thanks.
 
None, actually. You have a large rudder and a bow thruster, you don't need one.

Sorry
 
Before you buy one, in a more diplomatic way, a large rudder turned hard over can equal a stern thruster. That's what I do on my single screw boat. Do you know what the hard over angle is on your rudder? If you have an autopilot, it's often part of the display. To be truly effective in tight maneuvering, an angle of 40 degrees would be what you want. Sometimes the rudder and cylinder have this capacity, but electronic stops are programmed into the autopilot. They can be changed.

Ted
 
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My boat is single engine and doesn't have a bow thruster. There is not enough room to install one properly and no place close for the batteries. The only issue I have is getting the stern to do what I want when doing tight maneuvers. In reverse it just goes straight back with a hint of prop walk to starboard so its tough when doing a starboard tie in between two boats on side docks. I use the boat solo a lot and springing to get off a dock in a breeze is always tricky. I am not as quick and nimble as I once was.
 
I had my boat for 3 years and 600 hours. Bow thruster and big rudder. I went everywhere with no problem. I decided to add a stern thruster last year just because. Well let me tell you . It’s a whole new boat. I. Can now do a 180 in 15 seconds. No going forward to bump the stern over. Backing into a slip is now 1 smooth move. In addition it doubles the action of the bow thruster. I installed a Vetus 4hp with it’s own battery in the stern.
E9240CB7-3F95-4099-B697-371F655DA288.jpg
 
If you want a stern thruster, do it. We put one in 3 years ago and love it. We put a Sidepower that is about 8 hp. The Sidepower is a very nice thruster. I have gotten great support from Imtra who is the distributor. Whatever brand you go with do not go small, I went a size bigger and it was worth the few extra hundred bucks. It took me 2 days to do the install with a helper, very easy. As to bow thrusters have you looked at Exturn? They are a pod thruster that doesn’t take up much if any room inside the boat. Very easy install also.
 
Incredible.

The guy has made the decision to install a stern thruster and has asked for recommendations.

So far one response on point.
 
Menzies, my dear, neither is yours!

Sorry about the lack of diplomacy but I try and get to the point, not to soothe you and make you feel loved.
 
I see 2 responses on point and several that tell him to learn how to handle a boat. I have been driving boats for 52 years and know how to handle a boat but as I get older I also got smarter. I used to hustle from the flybridge to the stern to get to the docklines before the wind could blow the boat away from the dock. I was jumping over the dog, etc.. I realized that I was going to get hurt trying to be so fast. Now with the remote control I can leisurely walk to the stern and when the boat has blown off the dock I just push a button and the boat returns to the dock. No fuss and no rushing which IMO is much safer. We should be thinkig safety and not macho that I don’t need no stinking thruster because I know how to drive a boat. So if you want one, go for it. It will add value to your boat when you go to sell it. Maybe not all your money back but when someone looks at your boat and compares it to a boat without a stern thruster, your boat will likely sell first.
 
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Menzies, my dear, neither is yours!

Sorry about the lack of diplomacy but I try and get to the point, not to soothe you and make you feel loved.

Maybe he doesn’t have a stern thruster so he is not able to make a recommendation...
 
I see 2 responses on point and several that tell him to learn how to handle a boat. I have been driving boats for 52 years and know how to handle a boat but as I get older I also got smarter. I used to hustle from the flybridge to the stern to get to the docklines before the wind could blow the boat away from the dock. I was jumping over the dog, etc.. I realized that I was going to get hurt trying to be so fast. Now with the remote control I can leisurely walk to the stern and when the boat has blown off the dock I just push a button and the boat returns to the dock. No fuss and no rushing which IMO is much safer. We should be thinkig safety and not macho that I don’t need no stinking thruster because I know how to drive a boat. So if you want one, go for it. It will add value to your boat when you go to sell it. Maybe not all your money back but when someone looks at your boat and compares it to a boat without a stern thruster, your boat will likely sell first.

Would you reco the brand you have to the OP?
 
Would you reco the brand you have to the OP?

Absolutely, I thought that I had by saying it is a very nice thruster and that I had had good customer service. Maybe I actually have to say that I recommend Sidepower, which I do. No affiliation. Actually Sidepower has a great feature in that you can get or add on a variable speed feature so you can hold the boat to the dock while adding the dock lines. I don’t know of any other brand that does that although I have not really looked for it on other brands.
 
I have a stern thruster on a 32 foot trawler. My boat does not maneuver well under certain conditions at slow speed. I absolutely love using the thruster. Howver mine is a Dickson stern thruster and is older and hydraulic powered from a belt driven PTO from main engine. As a result it operates a bit different. The power output is correlated to engine rpm. Need more side thrust..bump up engine rpm. No battery bank needed. After talking to original owner it seems this hydraulic set up has been in use for atleast 20 years. And my understanding is there has never been an issue. And it still works flawless today. However before recommending them I would do some research on Dickson. They do not seem to have an internet presence so I don't know the health of the company currently. I love the product though.
 
I have a stern thruster on a 32 foot trawler. My boat does not maneuver well under certain conditions at slow speed. I absolutely love using the thruster. Howver mine is a Dickson stern thruster and is older and hydraulic powered from a belt driven PTO from main engine. As a result it operates a bit different. The power output is correlated to engine rpm. Need more side thrust..bump up engine rpm. No battery bank needed. After talking to original owner it seems this hydraulic set up has been in use for atleast 20 years. And my understanding is there has never been an issue. And it still works flawless today. However before recommending them I would do some research on Dickson. They do not seem to have an internet presence so I don't know the health of the company currently. I love the product though.

Try this link Welcome to Dickson Thruster
 
Thanks. The hydraulic units have some advantages. There is a bracket that allows for swinging the thruster 90 degrees and down which allows for using it as a get home option if your prop or shaft become unusable. But the engine obviously has to still run.
 
We have a 24V electric ABT TRAC stern thruster. Works OK, but service is difficult and expensive. If I was installing a new one, I would install a Sideshift www.Sideshift.com. Much less expensive, and installation and service much easier.
 
New slip for my Willard 36 will have some challenges, Like Comodave, I believe I have well developed boat handling skills - perhaps that's why I'm willing to admit that not all docking situations are solvable with a magic turn of the helm or bump of the gear.

As part of a refit, I thought about a stern thruster. However, several fellow Willard owners made rudder modifications and achieved good results. One is an articulating rudder that adds a trailing edge winglet that amplifies hard-over turns. The other is a "Fishtail" or Schilling Rudder that modifies the profile of the rudder and enhances flow and sideways thrust.

I chose the Fishtail rudder modification because there is no mechanical linkage. It's relatively inexpensive to do on my fiberglass rudder. Unfortunately, the boat is not yet back in the water so I cannot report on the effectiveness. But as I say, several other owners are impressed with the change and outcome. If that doesn't provide satisfactory results, I will try something else.

Good luck!

Peter
 
None, actually. You have a large rudder and a bow thruster, you don't need one.

Sorry

Do you have a GPS ? Why can’t you read a chart?
Do you have a sounder? Can’t you use a lead line?

These are 2 dumb questions . You have them because life is easier with them. So why judge the OP’s request for info.
 
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From the beginning, we found our boat very difficult to back up with any accuracy, mostly due to the very small rudder. So,over the first winter, we had a SidePower SR80-185T Retractable stern thruster installed. When the SidePower factory (in Norway) recommended to the dealer the SR80-185T, I pushed back as I thought it was way over-sized, given that the bow thruster that came with the boat was only an SE40. The factory explained that "oversizing" was required to offset the resistance from the stabilizing fins I have in the aft, as well as the significant amount of cabin "wind area" on a fairly light weight boat (13,000-15,000 lbs, loaded)

In the end, it turns out the Factory sizing recommendation was spot on. If I want to move away from an alongside tie up using both thrusters together, the boat stays parallel to the dock. Happiness. The "marriage saver":eek: feature of this installation has also functioned to perfection!

Over the years, I've honed my skills and have learned various tricks to compensate for the small rudder. Most of these tricks however, involve throttle, which I really don't like to use so heavily during delicate docking procedures. So, nowadays, I use the stern thruster a bit less than I did early on, but it's still a must-have, for my boat, in my opinion for so many reasons.

I've had this stern thruster for almost 10 years now and it's been trouble-free. Note, it absolutely requires a dedicated battery, mounted close by.

I considered the X-Turn (externally mounted) thruster mentioned earlier in this thread, but decided against it, as I did not want to introduce ~5% drag on fuel economy for the remainder of the life of the boat.

I've attached a spec below for information.

Good luck with your selection process!
 

Attachments

  • SR80_185T_spec.pdf
    2.1 MB · Views: 91
How many HP is your bow thruster? I think you will need a greater HP for your stern thruster.
Assuming you are using electric thrusters, you must consider the number of AMPS needed vs number of AMPs available.
My boat came with bow thruster off the start battery and stern thruster off the house batteries.
I change the bow thruster to the house batteries after added a 3rd AGM 4D house battery. The 4D AGM start battery now supports the just the main engine. Now I have both thrusters on the 3X4D batteries.
Reason? I have an electronic Cummins and that stops when the start battery drops to (I think) about 10.6 vts. Yup, had it happen to me while docking.
Now I realize, I could have paralleled all the batteries to save the day.

Opinions and recommendations are welcomed.
 
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When I got my boat , the bow thruster ran off the 8d house battery. I did notice sharp drops in volt gauge when I used it. To solve this I added a group31 Glass mat 2’ from the motor. I did the same with the stern thruster. I then bought 2 single bank 10 amp chargers. 1 for each battery. This isolated everything. If one system was to fail it can not cause any other problems. Also all charging systems are separate. I left the old power wires that went to the bow thruster in place but disconnected. Should I ever drain my 2 8d’s I can always connect them back to the thruster battery for an emergency start.
 
we had a bow and stern thruster. While the stern thruster did help with turning it was limited in its ability to bring the stern into the dock in even moderate breeze. So, my suggestion is if you plan to get a thruster, make sure it is big enough to really get the job done. I would oversize - additional cost is minimal once you commit to do the job. Also, make sure batteries are up to the job. These things draw a lot of amps.
 
I would definitely have a dedicated battery for each thruster. It is easy to do and doesn’t add a significant cost to the project. We added an Optima for the stern thruster with it’s own 15 amp charger. I still ran 4/0 cable even though it is only about 3’ run. The dedicated battery and heavy cable are a one time expense that will pay off the whole life of the system. Less problems with low voltsge, bad for the thruster motor and no problems for other systems on the boat like the engine if you have an electronic engine. Our total cost was under $4500 for the oversize thruster, battery and charger. Since I installed it there were no labor costs. It was a fairly simple install.
 
hmmmm, a thought..... AC powered hyd pump and then hyd thrusters.
Dumb idea? Sounds expensive to make the change over.
 
I think of the anti-thruster boaters as I do sail boaters! I bet they go to the dentist with a bad tooth and say no pain killer don’t try to save the tooth with your skills, just take a stick and a rock and knock the bad tooth out!
 
To solve this I added a group31 Glass mat 2’ from the motor. I did the same with the stern thruster. I then bought 2 single bank 10 amp chargers. 1 for each battery. This isolated everything.

I would definitely have a dedicated battery for each thruster. It is easy to do and doesn’t add a significant cost to the project. We added an Optima for the stern thruster with it’s own 15 amp charger.

A question for either or both of you: What type of chargers are these? What powers them?

I've never had a setup like this, but a few boats I've looked at have a bow thruster powered from the house bank. Looking at the amp draw, I'm not so sure I like what that might do to instruments, etc. Especially since I might want to use the thruster a bit in locks where you have the engine shut off.

Your "isolated" systems sound good, so I'm wondering where the chargers get their power and when.

(Figured this might be of interest to the OP as well.
 
A question for either or both of you: What type of chargers are these? What powers them?

I've never had a setup like this, but a few boats I've looked at have a bow thruster powered from the house bank. Looking at the amp draw, I'm not so sure I like what that might do to instruments, etc. Especially since I might want to use the thruster a bit in locks where you have the engine shut off.

Your "isolated" systems sound good, so I'm wondering where the chargers get their power and when.

(Figured this might be of interest to the OP as well.


This reminds me of something I didn't mention in my post. For the dedicated battery I added for my stern thruster, I use a DC to DC charger from the house battery. This has worked out well for me and allowed me to avoid having to re-do any portion of the original 12v battery charging setup that came with the boat.
 
Attached is a detailed description of my DIY install on my last boat.
 

Attachments

  • SternThruster.pdf
    1.5 MB · Views: 143
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