Bow thruster

[BruceK]

The Clipper 40 sold here, which mimics a Pacific Trawler(same builder I think), mostly with a single,starts life with a bow thruster. We looked at a number of them, most had a stern thruster added by the owners. We had one on our marina, I`ve been on it departing and returning, the experienced owner used engine for power and thrusters to steer.
The bow upgrade gives you a fresh new motor with a small power increase. Might be worth it. Starting at low speed you don`t get much steering from rudders.

 

[Greg S]

Hello Iggy.

You have two winners here. Jeff and Bacchus. They are describing two different stages of your dilemma. Jeff is describing getting your boat far enough away from the lift to start your 180 turn. Bacchus is describing the turn once you get out of the lift.
The reason the rudder, hard over to port, doesn’t cause worse stern movement to port on your initial reversing of the prop is that there is little or no water flowing over the rudder at that point. As soon as you apply forward prop the rush of water instantly starts turning the stern away from port and a short burst won’t start the boat moving forward, just turning. Alternating R with a short F will keep you going backwards and counteracts the prop walk. Try it! It’s awesome.
Once out of the confines of the lift, clear of the pilings, apply the teaching from Bacchus.
You may be able to increase the ability of your existing thruster by positioning the battery as close as possible, a foot or two away from the thruster motor, and still use large cables; 2/0 or as large as will fit.

 

[Jeff F]

Hello Iggy.

You have two winners here. Jeff and Bacchus.

And Greg for making complete sense of it all. Thanks. I think you're bang on.

 

[Iggy]

Thank you all!!

 

[Iggy]

Hello Iggy.

You have two winners here. Jeff and Bacchus. They are describing two different stages of your dilemma. Jeff is describing getting your boat far enough away from the lift to start your 180 turn. Bacchus is describing the turn once you get out of the lift.
The reason the rudder, hard over to port, doesn’t cause worse stern movement to port on your initial reversing of the prop is that there is little or no water flowing over the rudder at that point. As soon as you apply forward prop the rush of water instantly starts turning the stern away from port and a short burst won’t start the boat moving forward, just turning. Alternating R with a short F will keep you going backwards and counteracts the prop walk. Try it! It’s awesome.
Once out of the confines of the lift, clear of the pilings, apply the teaching from Bacchus.
You may be able to increase the ability of your existing thruster by positioning the battery as close as possible, a foot or two away from the thruster motor, and still use large cables; 2/0 or as large as will fit.

Ok, just to be clear. Rudder hard over to port. Reverse for 3 seconds than forward for one
second. Repit as needed. The boat should go straight back.

Once out of the pit. Rudder starboard and make my turn.

 

[Iggy]

For a once a year event there are other options to consider. Especially if your thruster is adequate for your other needs. An outboard dingy or skiff can be used. A RIB is it's own fender. Have the RIB driver work under your command. Position the rib to push which ever end you know needs to be pushed. I once turned an 85' single with no thurster in a space with less than 10' to spare. Not something I care to do very often but you are talking about once a year.

Just to be clear. Rudder hard over to port. Reverse for 3 seconds than forward for one. Repeat as needed. Once out hard starboard and make my turn. Urs?

 

[Arc]

Many boats will steer in reverse better with less rudder input. 10 Deg. Often better than 30 deg. Too much rudder and it’s just a barn door. Astern propulsion for,a short burst then neutral. This way prop walk stops quickly while you coast back .

 

[rslifkin]

Many boats will steer in reverse better with less rudder input. 10 Deg. Often better than 30 deg. Too much rudder and it’s just a barn door. Astern propulsion for,a short burst then neutral. This way prop walk stops quickly while you coast back .

Very true. If you're actually trying to steer in reverse (takes some speed on most power boats) you have to feel out the rudder behavior, as it's not uncommon to get a rudder stall at high angles in reverse. When that happens you lose most of the steering effect. Engine in gear vs coasting back in neutral will also change the stall angle in many cases.

 

[Portage_Bay]

Just to be clear. Rudder hard over to port. Reverse for 3 seconds than forward for one. Repeat as needed. Once out hard starboard and make my turn. Urs?

Iggy, you've gotten good advice here. The concept of using occasional bursts of power ahead to correct your astern course is solid advise. I don't think 3 seconds astern then 1 second ahead is a cookbook recipe you can follow. Do what is necessary in the moment to correct your course. Just don't use to much forward. All you want to do is move the stern sideways.

The image I posted in #26 showing how a boat steers in reverse was in response to your asking in post #25 if rudder to port going astern causes the stern to move to starboard. It does not. Steering a boat moving astern has almost no bearing here because you don't have enough room to build enough sternway and allow the boat enough time to turn. I apologize for any confusion I caused.

Now you are quoting my post #20 where I suggest using a RIB to help but asking about rudder again. The two techniques have nothing in common. The RIB used skillfully can be compared to a thruster. But far more powerful with no time out from overheating the motor.

I will give one more suggestion. Your boat backs to port. The obstacles you are trying to avoid lie close to port. What might work is a short ahead with rudder to port before the first astern. This may set you up in a move favorable alignment. But only if there is enough room to try it.

You seem to be looking for a step by step procedure you can follow. There aren't any. Learn the basics, learn your boat, adjust as necessary.

 

[angus99]

I’m having a Vetus bow thruster installed next month on our 44 with 330 lbs of thrust. This is one level higher than recommended, but having been caught with an under-powered thruster once, I don’t want to experience that again. The larger installation companies have put thrusters on hundreds of boat models (Florida Bow Truster claims 1,300 models). If you decide to upgrade, they can likely recommend what will work with your boat.

 

[Iggy]

Thank you again.

 

[ranger58sb]

And yes a single screw. If it was a twin I would not have this problem!

Fair enough. And subsequent conversation eems to be addressing that nicely for you. Including the comments about spring lines and PB's suggestion just below about maybe trying a bit of forward first, if there's space.

I will give one more suggestion. Your boat backs to port. The obstacles you are trying to avoid lie close to port. What might work is a short ahead with rudder to port before the first astern. This may set you up in a move favorable alignment. But only if there is enough room to try it.

Another possible maneuver, not sure I saw anyone mention it, is maybe to see about backing into your fairway and into the travel lift. You might have easier (enough) steerage that direction n the way in, and better steerage on the way out. Assuming your boat can be lifted that direction.

So back to some of your original question. If the maneuvers aren't improving things for you, yes I might consider the intermediate move to a slightly larger motor on your existing thruster.

And if THAT doesn't solve it (including the suggested maneuvers) you might consider installing a stern thruster instead of supersizing the bow thruster.

Back to spring lines: You will benefit greatly by learning and using those, if you're not already. !!!!! (We use spring lines routinely, even with twin engines and a bow thruster!!!)

Back to prop wash: You can often make that work in your favor... with practice.

-Chris

 

[rwidman]

This is going on my 3rd year. I think its underpowered but I have nothing to gauge it on. Maybe a expect it more than I should?

At $1,100 the hit I can take! At $3,500 plus will hurt. But will I gain anything?

I originally thought my bow thruster was underpowered, but as I learned to operate the boat, I learned how to use it properly. It's fine.

Work with yours for a while before you spend big money replacing it.

 

[Pete Meisinger]

I have to assume you have a power boat, not a sailboat. Tell the yard you want it put in 180 degrees from what they usually do. They should be able to accomodate you.

pete

 

[rslifkin]

Another possible maneuver, not sure I saw anyone mention it, is maybe to see about backing into your fairway and into the travel lift. You might have easier (enough) steerage that direction n the way in, and better steerage on the way out. Assuming your boat can be lifted that direction.

That's a good point. Usually the travellift can only drive over the pit in 1 direction, but depending on the lift design and height of your boat (as well as any constraints on how they're getting it in/out of the lift once it's on land), it might be possible to lift the boat either direction. I know at the yard we store at for winter, we fit in their travellifts facing either way. Sailboats and powerboats with tall flybridges usually fit better 1 way than the other, however (usually bow first for powerboats, stern first for sail).

 

[Iggy]

I have to assume you have a power boat, not a sailboat. Tell the yard you want it put in 180 degrees from what they usually do. They should be able to accomodate you.

pete

I mean this in the best possible way. I already thought of that. That would be a no brainer.

 

[Jeff F]

I will give one more suggestion. Your boat backs to port. The obstacles you are trying to avoid lie close to port. What might work is a short ahead with rudder to port before the first astern. This may set you up in a move favorable alignment. But only if there is enough room to try it.

Yep. With practice this is a great technique. Even easier if you go forward against a spring line, watching the bow. Then you can get the stern well to starboard before starting reverse movement, which is going to pull the stern to port.

First step is getting comfortable with shift and throttle to learn how the boat responds. Then use it.

 

[Portage_Bay]

First step is getting comfortable with shift and throttle to learn how the boat responds. Then use it.

And get comfortable with neutral. There is no prop walk in neutral, spend more time drifting astern.

Of course this only works if there is no adverse wind or current. Which brings up another point. Along the lines of Pete M's suggestion. If the yard won't launch you bow out schedule the launch when conditions are favorable for you not convenient for the yard.

 

[Jeff F]

And get comfortable with neutral. There is no prop walk in neutral, spend more time drifting astern.

Good point. You don't always have to be in gear. Just understand the R pulls the stern to port and F pushes it to starboard, and balance that while also controlling boat speed. This is true moving slowly forward, stopped, or moving slowly back, with the rudder fixed in position.

My experience is that throttle also plays a big role. Usually a brief throttle increase exaggerates the side movement in either direction before really changing the speed of the boat. Getting that right allows you a lot of control. It varies by boat, but the principle is pretty universal.

 

[Jeff F]

Just to complete the loop here, once you are moving at any speed in a more-or-less straight line backwards, straightening the rudder may allow you to transition to actually steering backwards as shown in the diagram. But you need to be going fast enough to overcome the prop torque when in R.

On my boat the transition is about 2 knots backward speed. Depending on prop torque the OP's is probably similar, maybe a bit less.

In practice I rarely steer in reverse. Far easier to be patient and stand at the controls bumping shift and throttle.

 

[Jeff F]

That's a good point. Usually the travellift can only drive over the pit in 1 direction, but depending on the lift design and height of your boat (as well as any constraints on how they're getting it in/out of the lift once it's on land), it might be possible to lift the boat either direction. I know at the yard we store at for winter, we fit in their travellifts facing either way. Sailboats and powerboats with tall flybridges usually fit better 1 way than the other, however (usually bow first for powerboats, stern first for sail).

This just solved for launch while creating a nightmare approach for haul

 

[rslifkin]

This just solved for launch while creating a nightmare approach for haul

That depends on what they're doing with the boat after it's lifted and what their layout is. It could be possible to pick the boat up facing one way and launch it facing the other way depending on what the land side of the operation looks like.

 

[Jeff F]

That depends on what they're doing with the boat after it's lifted and what their layout is. It could be possible to pick the boat up facing one way and launch it facing the other way depending on what the land side of the operation looks like.

Oh yeah. Suppose so. Most storage yards I've been around have strong preferences, but now that I think about it, generally it's bow in on entry, bow out on exit at a yard I'm very familiar with. Sorry, didn't think that through. Sometimes there are constraints against the cross beam as well.

 

[rslifkin]

Oh yeah. Suppose so. Most storage yards I've been around have strong preferences, but now that I think about it, generally it's bow in on entry, bow out on exit at a yard I'm very familiar with. Sorry, didn't think that through. Sometimes there are constraints against the cross beam as well.

Yup, the cross beam on the lift is often the biggest constraint. If the boat clears the cross beam when lifted either direction, and the cross beam fits over the top of the boat when it's either blocked, on a hydro trailer, etc. then there's usually flexibility in which way it faces in the lift for each operation.

 

[Jeff F]

Yup, the cross beam on the lift is often the biggest constraint. If the boat clears the cross beam when lifted either direction, and the cross beam fits over the top of the boat when it's either blocked, on a hydro trailer, etc. then there's usually flexibility in which way it faces in the lift for each operation.

That's likely why the OP is launched backwards.

Doesn't matter. Not being able to control the boat when reversing is a pretty big handicap. The OP should solve for it regardless.

 

[backinblue]

As a few had mentioned earlier, maybe a stern thruster is a better thing to look into rather than a bigger bow thruster. It will cost some boat $$$ but would certainly help with manuverability especially when backing into something. Yes, by moving the bow you can point the stern, but in close quarters it's good to have that direct control. It's also much easier to spin the boat in its own length by operating both thrusters as well as walking the boat sideways if needed.

 

[Iggy]

That's likely why the OP is launched backwards.

Doesn't matter. Not being able to control the boat when reversing is a pretty big handicap. The OP should solve for it regardless.

Thats right. Thats way it does in bow first pointing into the shore line. Launching is the same way. The operator says the boat can not be turned around for many reasons.

 

[Iggy]

As a few had mentioned earlier, maybe a stern thruster is a better thing to look into rather than a bigger bow thruster. It will cost some boat $$$ but would certainly help with manuverability especially when backing into something. Yes, by moving the bow you can point the stern, but in close quarters it's good to have that direct control. It's also much easier to spin the boat in its own length by operating both thrusters as well as walking the boat sideways if needed.

As mentioned. There is a fuel tank in the stern. you can not bolt one on. But there is an open space left and right of the tank. New England Bow Thruster looked at it and the wanted to put in two thrusters that lower them self's into the water. Bigger bucks!!

 

[backinblue]

As mentioned. There is a fuel tank in the stern. you can not bolt one on. But there is an open space left and right of the tank. New England Bow Thruster looked at it and the wanted to put in two thrusters that lower them self's into the water. Bigger bucks!!

Does the tank run the full width of the stern? Doesn't really matter if the thruster is centered. I don't see why you would need 2 unless they were 2 small ones to equal 1 of adequate size. Also don't know why they would need to raise and lower unless they are below the hull bottom when lowered.

 

[Jeff F]

As a few had mentioned earlier, maybe a stern thruster is a better thing to look into rather than a bigger bow thruster. It will cost some boat $$$ but would certainly help with manuverability especially when backing into something. Yes, by moving the bow you can point the stern, but in close quarters it's good to have that direct control. It's also much easier to spin the boat in its own length by operating both thrusters as well as walking the boat sideways if needed.

Agreed.

A little personal anecdote: my previous boat was a Mainship 34 MY. No thrusters.

I grew up on the east coast and cut my teeth driving boats like the fishermen did. I kind of enjoyed driving the Mainship the way it was. It forced me to think about springs, and to use them on occasion.

I guess I should say that I operate solo and cover a lot of territory.

My current boat is 50 ft and came with bow and stern thrusters, and the old owner took my Mainship on trade. He told me that he had added the stern thruster and really liked it. I was skeptical. At one point I suggested that he keep the Sideshift thruster and its 4 batteries supporting it for the Mainship.

I'm glad he didn't take me up on the offer. My boat has gobs of prop torque and limited visibility aft from the steering position. Going backwards was challenging at first, and the stern thruster helped a lot with that, as well as routine dockside maneuvers.

I now have about 11k miles on the boat, and the stern thruster quit about 7k in. I'm stopped now doing a few updates and repairs. I expect that Sideshift will help get it operational at a reasonable cost, and it's on my list.

There was only one time I really missed the stern thruster. I was on the Illinois River approaching a lock from the bottom with a strong tailwind. 30 knots plus. The lock master insisted that I secure starboard side to the chamber.

I could have done it with a helper, but without the thruster I couldn't stop the boat without the stern swinging out and catching the wind. After a couple of aborted attempts they closed the gates and allowed me to free float during the lift. Problem solved. If they'd offered the port side tie up it would have been easy.

So I love my stern thruster, but I don't view it as a must-have. And I'd always advocate learning a few tricks before adopting its use.