Unique bow thruster install.

[mvweebles]

As rflifkin states, stern is pretty maneuverable with twins - key is to first understand prop-walk, and second, treat the two engines as two singles with opposing props. In reverse, the 'outboard' engine (the one furthest from a side-tie) will always pull the stern towards the side-tie.

I used to move a lot of boats for boat shows and such. I developed a routine that I would tweak a bit depending on how the boat moved.

1. Aim for a point about 1/4 boat length back from the boat in front. Maybe closer. As long as I was certain the slot was big enough to fit my boat, I would work to keep the boat as close to the boat in front as possible. Forward would be granted by the inboard engine (closest to dock) to initiate turn. Keep it slow. I'll repeat - crowd the boat in front and you won't have to worry about your stern swinging into the boat in back.

2. Working from the flybridge, when the dock starts to disappear due to bow-flare, drop the outboard engine in reverse. This will immediate start the stern towards the dock without rotating the bow away from the dock, and slow the boat. Feather the RPMs in reverse to modulate speed and prop-walk.

3. By this point, you have decent rotation into the dock. If your stern is swinging too fast and risks bouncing off fenders, put the inboard engine in reverse and it will immediate check rotation using prop walk. Clean-up the landing with both engines.

In Step #2, why not 'split the gears' with right engine in forward, and left engine in reverse? Because it will swing the boat away from the dock and you'll end-up several feet away from the side-tie.

If you need to extract mid-maneuver (perhaps you're worried about swinging into the boat behind you), drop the inboard engine in reverse - this will rotate your stern away from the dock and drag you away.

Leaving the berth is not quite exactly the reverse. Base move is to back-away from the side-tie. To start the rotation, I use what I call "dip the bow." A slight 'burp' of forward gear to the outboard engine to get the boat moving forward just a bit and to start the rotation away from the dock. Then the inboard in reverse - prop walk immediate pulls the stern away from the dock, and of course any forward momentum from "dipping the bow" is negated.

At least that's my process. It's worked well for me, even on large boats.

Peter

 

[rslifkin]

That's basically the process I use on a side tie (or coming into a lock) as well. Works quite well and is easy to adjust for wind, current, etc. I typically give a quick shot of idle reverse on the inboard engine right at the end just to cushion the landing.

A modified version of this where you approach 180 degrees from your desired direction, start turning, point the nose in, then pivot the boat around as the bow slowly gets closer to the dock works quite well also, although it's harder to do with wind and current. Works very well in a tight spot though, as you end up moving in a bit more sideways than with a same-direction approach (so you need less space on either end of the boat). It does generate an interesting combination of nervous and impressed looks though.

The biggest thing to remember is that you're not trying to make the boat "go that way now", you're using thrust, prop walk, etc. to adjust the momentum the boat already has. That's why the outboard engine in reverse while moving forward works so well to pull the stern into the dock. The forward motion helps keep the bow from pivoting out while thrust slows you down and prop walk pulls the stern in.

 

[ctjstr]

I have a friend who installed one on his 4388 Bayliner. He loves it. When he's moving forward at any speed, it pretty much rises out of the water so no drag. Obviously not so when at hull speed. I wouldn't want one, but they have at least one happy customer.

toni

 

[Comodave]

I like the concept, and looked at the Side Power one.


While my current boat has the tunnel, the boat's I'm shopping for, most don't have a thruster. I'd strongly consider an external, especially when there install issues with things in the way for an internal.



Now, question for you twin drivers....


What's your thought on a bow vs stern thruster with twins? With a twin set up it's pretty easy to move the bow, but almost impossible to move the stern.

We have twins. I put a stern thruster in about 3 years ago. My reason was that we only have an upper helm by choice. When docking my wife handles the bow lines and I do the stern. Our lab stays on the bridge until I start down to the sundeck, then he wants to be first. At first I would rush to get to the dock line before the stern would blow away from the dock. I decided that I was either fall and hurt myself or fall on the dog and hurt him, or both. So I installed a Side Power thruster in the stern, easy 2 day install. Now I can leisurely walk from the helm to the stern and use the remote control to move the stern back to the dock. I will eventually put in an Exturn bow thruster when I get to it. I love my stern thruster.

 

[tekdiver]

bow thruster

I was at a yard in Oceanside CA (north of San Diego) the other day and spied this unusual bow thruster install on a Bayliner 38. Does not appear to be functional anymore. Wonder why?

Peter View attachment 109797

https://shop-us.sideshift.com/colle...thruster-products/products/ss230-bow-thruster

 

[tekdiver]

4000.00

 

[cappy208]

Slip has one. Installed around 2012. I purchased said contraption in 2014. Has been working fine all along.

It does eat up zincs like crazy.

My brother has said: ‘When that thing dies, we’re ripping it off the boat’.

Still waiting.

 

[Juggerknot]

May as well just have a long-shaft trawling motor mounted on the bow rail for when you need it, what a turd in the punchbowl this thing is!

 

[Comodave]

I’m just glad it’s not my punch bowl...

 

[Juggerknot]

Roger that!

 

[LenBuchanan]

A guy two slips down from me has a 45 Riviera, long low and sleeky looking boat. He has one that is similar to the one shown. He says that when he is cruising, enough of his bow is out of the water, that there is no drag on the thruster and that the thruster is out of the water, but to me, it still seems like a lot of drag and pressure on the thruster as soon as you slow down.

 

[Arc]

This is a unique set up

 

[Juggerknot]

With the limited space due to shaft way, the 2 smaller thrusters are a good work around...