Bow Thruster Placement

[RobertoG]

I will be closing on a 2008 Beneteau 43 the beginning of February. I am hoping to install a tunnel thruster in the bow. I had forgotten that one of the water tanks is in the bow beneath the berth, and I don't believe there is enough space to leave the tank and install the bow thruster. One option I have is to get rid of the water tank as I have another one in the aft berth. Another option is to install a smaller water tank. Has anyone had to deal with this type of installation, and what was your solution?

[Tillsbury]

I'd keep the water tank and forget the thruster. It's way more useful.

[billknny]

I have a boat that NEEDS a bow thruster. Your future boat is quite nimble and does not need one.

If you are worried about handling it, take one quarter of the money you might have spent on the thruster and get some good lessons on docking. They will serve you well.

[RobertoG]

Definitely an option. Do you have a bow thruster on your 50' Bavaria?

[RobertoG]

I may be doing some single handed sailing and a bow thruster seemed to be a good addition when the wind picks up and there is no one on the dock to assist.

[Tillsbury]

Originally Posted by RobertoG

Definitely an option. Do you have a bow thruster on your 50' Bavaria?

No, and I had budgeted to install one first thing as I've not had a boat this size before and will always be single handing. But after a couple of weeks I realised that it's no different from dealing with a smaller boat. If anything easier as the larger the boat the less significant windage is compared with the stability and predictability gained by increased mass (one increasea by the square, the other by the cube of length).

In any lightish wind (under 20kts abeam) it's not hard to moor, as long as you take the usual precautions and approach sensibly. Anything more than that, the bowthruster isn't going to help and you're aiming at the wrong pontoon. Go somewhere else temporarily.

And there are a couple of points I hadn't considered that have been mentioned on other threads: if you get used to boat handling with a bowthruster you will not gain the experience necessary to manoeuvre safely when it's not there or when the conditions make it useless. And secondly, approaching a dock in conditions where you will definitely need the bowthruster leads to the possibility of it failing and you finding yourself in trouble.

Add to that the downside of a big hole in the bow of your boat and the not insubstantial cost and it's moved so far down my wish list it's fallen off the bottom.

Far better to spend the money on something useful like a new mainsail or a generator, then spend a day or so practising manoeuvres and enjoy being able to handle the boat without issue.

[Tillsbury]

Also, two independent water tanks is a very significant safety feature I would not be without. On more than one occasion I've "lost" a water tank (through plumbing failure leading to the entire tank being pumped into the bilge, or by it being filled from a flaky water supply). Without the ability to manually switch to another tank life could have got pretty unpleasant, particularly if we were further from land than we were.

If you do remove the tank make sure you put another one in somewhere else. I too have a forward water tank and I keep it half full as "emergency reserve" in case of problems with the main tank, but ensuring there isn't too much weight in the bow unnecessarily.

[valhalla360]

What type of cruising are you planning? Off shore, it may be nice but coastal far less critical.

[Dockhead]

Originally Posted by RobertoG

Definitely an option. Do you have a bow thruster on your 50' Bavaria?

Bow thrusters are wonderful things with a long list of really useful things you can do with them, like move the boat sideways off a dock to get out of a narrow spot, steer by the bow when going in reverse, line up the boat to get dock lines on, etc. etc. etc.


That being said, you don't strictly speaking need it on a boat that size. You can do most of what a bow thruster is handy for with spring lines and the muscles of your crew. When a boat is big enough that you can't shove it around with muscle power (say, over 20 tonnes) then bow thrusters start to become more essential.



If you do install a bow thruster, make sure it is powerful enough. Many boats that size get underpowered thrusters which aren't of much use.

[Pete7]

If you have some space, this might be an alternative.

https://www.hambleyachtservices.co.u.../jet-thruster/

Thankfully this and a water maker are two things I don't have to worry about.

Pete

[Dockhead]

Originally Posted by Tillsbury

. . . In any lightish wind (under 20kts abeam) it's not hard to moor, as long as you take the usual precautions and approach sensibly. Anything more than that, the bowthruster isn't going to help and you're aiming at the wrong pontoon. Go somewhere else temporarily.. .

You don't need a bow thruster at all for getting onto a dock. I never use mine for that. And I agree with you that if you are trying to get on being blown off in 20+ knots, no bowthruster is going to solve that problem.


But where it is supremely useful is maneuvering in a tight marina, especially in reverse. Sometimes you need to be able to get the boat sideways or correct the position of the bow independent from the stern. Without a bow thruster in such conditions you pretty much have to go really slow and have crew push you off as needed. With wind or current and no thruster this can be a dangerous situation single handed. WITH a bow thruster you have a huge amount of control -- put the rudder over in the opposite direction from the thruster and this creates creates lateral movement. Steer bow and stern separately to make your boat go in any direction you want.

Also really useful getting off docks without scratching the top sides, or if the berth is really narrow. Mostly you can do the same thing with spring lines, but the thruster is really handy, especially single handed.

I use spring lines A LOT -- it's part of the art of harbor maneuvers, and something worth being skilled in. In many cases a spring line is a BETTER solution than the thruster -- it's more powerful. To get off a dock while being blow on in 25 knots of wind, a spring line is actually the only solution -- spring the stern out (then use the thruster to keep the bow from scraping the dock) and back out. But single handed you often cannot use a spring line -- so the thruster is awfully nice (but single handed and being blown on by 25 knots of wind I would not be able to leave).

Yet another really handy use of a thruster is to correct the position of the bow when setting the anchor. There are too many to list, but on the other hand a thruster is not a panacea and certainly is not a substitute for skill.