Bow Thruster vs Stern Thruster

Guess

My wife has a very simple way of remembering what shifter does what with our twin. She envisions moving the shifters as moving her whole body. So right shifter back, left one forward swings her butt (stern) to the left. Left shifter back, right one forward swings her butt (stern) to the right.

I was taught to treat the shifters like the steering controls on an older-style bulldozer. One shifter forward, the other in neutral, boat pivots slowly away from the forward shifter. One shifter forward, the other in reverse, boat pivots rapidly away from the forward shifter.

Pau Hana said:

We're contemplating one of these:

Yacht Thruster - Bow and Stern Thrusters Applications


Seems perfect for a DIY project, and I like the idea of a small hole in the boat vs the traditional tube. The company touts the exposed motor has extended run time due to the cooling action of the surrounding water.

Last time I checked pricing it was in the neighborhood of 5K (including haulout for the unit install). The haulout can be a haul and hang vs blocked.

Opinions?

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wow that is a great idea. Reading the install instructions it requires mounting in the exact center of bottom. Dosent this mean you will need a 2.5' hole drilled through the keel? That scares me a bit.

With the rudder amidships in close quarters, you drive a twin screw like you push a shopping cart.

Moonstruck said:

With the rudder amidships in close quarters, you drive a twin screw like you push a shopping cart.

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Absolutely hate those shopping carts with four-wheels able to all swivel.

Yacht Thruster Brand

I recently got a quote for a Simplex 300 (larger of the single prop models), thinking to use it as a stern thruster as we already have a Vetus bow thruster. The cost was going to be just shy of $8k, not including the batteries to power it. We were going to install it our self so that price is for hardware only, which I did not think was out of line, all things considered.

Moonstruck said:

With the rudder amidships in close quarters, you drive a twin screw like you push a shopping cart.

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Great analogy Don.

rwidman said:

It seems like that would be pretty inefficient at high power. And pretty expensive. Would two 12 volt batteries in series have been an option?

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Old thread I know but .............

An inverter chamges DC to AC so is not applicable in this situation.

Two 12volt batteries can be connected with a series/parallel switch ( just a large solenoid) available from any farm equipment outfit for about $150. Many tractors start on 24volts and run everything else on 12volts.

This switch allows you to charge the batteries independently from a 12volt alternator (or charger) and is wired into the joystick to engage both batteries for 24 volt output.

Vetus also makes a series/parallel switch but last time I checked it was $1500 and not as robust as the one from the tractor shop.

That's how our stern thruster is setup. When I press the on button at the helm it isolates the two 8D's from the buss then it puts them in a series so I can get 24v.

Here's what it looks like.

A bow thruster is more desirable. Both is better. Hydraulic motors usually require you run your generator when you need to use them. If the main engine is used, there is the need for more RPMs. When you are docking at idle speed you may not have enough power for the pump. I would go with a good quality electric (constant run) motor, dedicated battery bow thruster. Then save your money and add a stern thruster next year, if needed.

Chester

N4712 said:

That's how our stern thruster is setup. When I press the own button in the helm it isolates the two 8D's from the buss then parallels the two 8D's so I can get 24v.

Here's what it looks like.View attachment 33992

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Series. the new circuit is series. parallel doubles Amperage.

eseyoung said:

Series. the new circuit is series. parallel doubles Amperage.

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Yep, sorry one eye is still closed!!

boatpoker said:

Old thread I know but .............

An inverter chamges DC to AC so is not applicable in this situation..

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I know that, I was responding to someone else's post.

Moonstruck said:

With the rudder amidships in close quarters, you drive a twin screw like you push a shopping cart.

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Full of cold beer?

Until my current boat, I hadn't had a bow (or stern) thruster, but didn't feel like I needed it (even on a 55' boat) and considered it more of a crutch for those not skillful enough to maneuver a twin engine (single engine is a whole different story) boat.
With my current boat, I use the bow thruster all the time. Kind of reminds me of the scene from indiana Jones where he is fighting the 10th consecutive sword-bearing muslim using only his whip. Finally indianna just pulls out his gun and shoots the guy. Like using a gun in a sword fight, using a thruster certainly makes challenges easier.

stern thruster.

Curt, I have a MS1 single eng. last winter I installed a lewmar 185tt thurster on my boat. The reason I went the stern was cost,$8500 from northeast thruster. This was a DIY job just cut big hole! BEST $3500 I ever spent on this boat . backs out , backs down ,& spins around in her own length. Would a bow thruster be cool too,sure,but right now I don't see the need for it. Everyone in my marina was amazed how good it works! BUT, make sure you can get the thruster down deep enough in the water,if not all you will do is suck air. If you look at a VETUS systems ,they make bolt on thrust diverters . you will most likely need them. Hydraulic is no doubt more dependable,if you already have a pump & stuff, but elect. is fine. Good luck, Rich.

My experience with thrusters. Two(bow & stern) are better than one and pair that with twins and you can maneuver with the IPS boats.

Eyschulman,
I agree but in keeping w the OP I'd say stern. One can back straight w a stern thruster and that's about the only time I need more control w Willy. Backing out of slips or into them but the one time I'd really would like one is backing down on an anchor in the wind.

psneeld said:

Full of cold beer?

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Not for long with me around

Bow Thruster

I had a bow and stern thruster installed on my Mainship 390, Docking by Control did the stern. Danny did an awesome job, he really knows his stuff. Now that I have them, I wouldn't want to drive without.

explorer72 said:

I had a bow and stern thruster installed on my Mainship 390, Docking by Control did the stern. Danny did an awesome job, he really knows his stuff. Now that I have them, I wouldn't want to drive without.

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Very nice. Congratulations.

I don't think I could get into many of the places I have without them.

explorer72 said:

I had a bow and stern thruster installed on my Mainship 390, Docking by Control did the stern. Danny did an awesome job, he really knows his stuff. Now that I have them, I wouldn't want to drive without.

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+1 for Danny at Docking by Control. They performed the installation at Seabrook Shipyard in Texas. Fine work and love the C-Marine thruster he recommended for my installation.

To me it is a safety issue. With just me and my wife (neither one of us is exactly nimble or fleet of foot) I found that I can hold the boat against the dock while she gracefully steps off and secures the breast line... Both just make life a little safer and easier... and yes this old gal has fore and aft thrusters

The issue of bow and or stern thrusters has evolved. Time was members would be criticizing having bow, let alone stern, thrusters. I see sense in them but have neither, I`d like a bowthruster, but the economics don`t work unless for sure I keep the boat long term.

While shopping for a GB 32 I have test driven boats with both bow and stern thrusters. Not a huge difference in manuverability, but I think the stern thruster I used shoved the stern around a bit faster than a bow thruster shoved the bow around. I have pretty much settled on a Dickson hydraulic ,stern unit for these reasons...less total cost, maybe $5 or $6K total, Much smaller hole in boat, just some bolts and hydro lines, not a 4 or 5 inch hole like the electric ones, no need for dedicated battery, maybe quieter.
My 2 cents...
Oldersalt

Ka_sea_ta said:

To me it is a safety issue. With just me and my wife (neither one of us is exactly nimble or fleet of foot) I found that I can hold the boat against the dock while she gracefully steps off and secures the breast line... Both just make life a little safer and easier... and yes this old gal has fore and aft thrusters

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Precisely why we have both.

Drake said:

Precisely why we have both.

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I get the need, or at least the want, of a bow thruster on smaller boats. But the NEED for a stern thruster some what baffles me.

Since all boats come with stern thrusters, in the form form of props and rudders. Especially boats with twins.

Capt.Bill11 said:

I get the need, or at least the want, of a bow thruster on smaller boats. But the NEED for a stern thruster some what baffles me.

Since all boats come with stern thrusters, in the form form of props and rudders. Especially boats with twins.

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....I too agree that thrusters are a "degree" of making docking easier, safer, etc....

And that some actually prefer the stern thrusters.

I guess like any tool, the better you get at using it, the more it becomes natural......

I hope someday I can get back to running a boat with a thruster.....life should be getting easier, not tougher!

Capt.Bill11 said:

I get the need, or at least the want, of a bow thruster on smaller boats. But the NEED for a stern thruster some what baffles me.



Since all boats come with stern thrusters, in the form form of props and rudders. Especially boats with twins.

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I understand your point but....

I came from a 40' sailboat with No bow thruster. There were times when a bow thruster would have been nice, but with a big rudder and prop walk, I never even thought about a stern thruster.

Now it is different. I have a boat with a lot more windage, tiny rudder, and while it has prop walk, it isn't nearly as pronounced as the sailboat (likely because my boat is heavier with no fin keel). I still try to use the thrusters as little as possible. I want to develop my skills, and save wear on the gear. I guess I view the thrusters as an adjunct as opposed to a primary tool. However, there are simply a lot of places that I would not be able to get into without them. In those situations I use them happily.

dhays said:

...
I came from a 40' sailboat with No bow thruster. There were times when a bow thruster would have been nice, but with a big rudder and prop walk, I never even thought about a stern thruster. ...

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Have a bow thruster only on my single-engine boat. Don't feel particularly handicapped without one on the stern. With judicious use, rudder and propeller can maneuver the stern, but less simply than a stern thruster.

How much complication does one want in the way of engines and motors? Twin propulsion plants, a genset, a bow thruster, auto-pilot, and a stern thruster?