bow thruster install

hi joe,
actually i'm an experienced operator of both single and twin engine vessels, large and small. this is just an add on i'm considering. it's kind of a new gadget, look at what i've got now and check this out, type thing.
no matter one's experience, a bow thruster is just fun to have and at times is worth it's weight in gold.
thanks
pat
 
I've gotten a lot of experience with thrusters in a short time since buying the WC 46. Bob is giving some good advice as usual. Our boat came with a Vetus bow thruster. Nothing wrong with it except it needs to be larger to move the boat around in the wind. Go with a size or two up from what you think you need.

I added a stern thruster to the boat last fall. I did it because our boat with a single Cummins inboard walks hard to starboard in reverse. I went with a larger thruster and it works very well.

I would add a dedicated battery and switch to any thruster. They take a lot of power and a separate battery and short wiring run make a difference.

From what I now know, if I was adding one thruster it would be a stern thruster on this boat. I think I could always get my bow to the dock, it's my stern that is the issue. I thought the stern thruster would be less costly because it wouldn't need a tube. I was wrong, it required tubes for the stern also and cost as much or more than a bow thruster.

Having both bow and stern thrusters is wonderful on this boat. It is infinitely maneuverable around the dock. You can see pictures of the installed stern thruster in my album.
Lyle
 
In a larger vessel, with a lot of windage, even with twin screws, a good bow thruster is still a nice addition. The place where it is of most value is getting of a dock with either a beam wind or current, and not enough room to maneuver fore or aft. In that case, the stern can be walked out, and then the bow either thrusted off, or held in position, and then sternway to bring the boat out of the "hole". Yes, you can use a large ball fender on the bow, to take any pressure of the bow agains the dock, but the thruster makes it easier.

There is another way--in a pinch--and that is to use a kedge anchor abeam--and use a windlas with a snatch block or a dedicated winch for or aft, to pull the boat off the dock (or conversely ease it onto the dock, using a kedge anchor).

Dickinson is still around and making the stern thrusters which run off the Westerbeke gensets--for about an extra $1000, you can get a modifaction which allows the stern thrusters to give foreward thrust and act as a "Get home" system.

Generally I/O's work the same as outboards in maneuvering. The Bravo III (or Volvo comperable units) have counter rotating props, and thus there is no "Walking" of the stern from the torque of the prop rotation in different density water--or paddle wheel effect on backing down.
 
ok, my original post was requesting information regarding bow thrusters. my c-brats friends chimed in and as a direct result, i have ordered a vetus 3512 electric bow thruster, with the joy stick control as well as a hand held remote control. actually, it was capt. dr. bob who had mentioned the vetus brand, so, with that in mind, i contacted florida bow thrusters as well as east coast bow thrusters and each provided me with a quote. florida bow thrusters won and will install the thruster on june the 28-30. originally they quoted a 2500 thruster, but again you guys told me to go one greater than the model called for and thus the 3512 will be installed. so, just wanted to say thanks, i will post pictures of the install as it happens.
best regards to all,
pat
 
as a follow up to charlie, letting the cat out of the bag, linda and i decided to write down everything we wanted in OUR LAST BOAT. first, it had to be affordable, meaning no payments, second, had to be legally trailerable, had to be a non-smoker prior owner, no exceptions on this one, had to have a generator, head with shower, comfortable and easily entertain up to six. we also demanded that OUR LAST BOAT be such that when something went wrong, mechanics and parts would be readily available.
what kepped popping up was the sea ray brand. we looked at the 280 model, loa 31' but had a beam over the limit, and then the 260 model, loa 28' beam 8'6". perfect!
our search focused on the 260, single engine, tried and true, mercruiser 350 mag 300hp engine with bravo 3 outdrive.
found the boat in grant, alabama, erwin marine sales. so, this is what we now have:
2006, sold new in 2007, 260 sundancer model, cinnabar colored hull, with black bottom paint, 2007 aluminum tri axel trailer, 350 mag engine with 45 hrs, 5000 watt kohler gen with 27 hrs. vacuum flush head/shower system, with overboard discharge, factory installed 10" flip down tv/dvd, navman 5500 gps, (i will replace that with a raymarine radar/gps system) marine heat and air, premium am/fm/cd stereo, remote spot light,
full galley, frig/sink/microwave/stove, trim tabs, vhf with external speaker,
black cockpit cover, full black camper canvas, fiberglass radar arch, windlass, and did i say bow thruster!
so, we enjoyed our c-dory, took great pride in ownership/care of our "misty seas" but it was time to move on and as mentioned before, now have OUR LAST BOAT!
haven't decided on a name, as of yet. always interested in suggestions. i will post pictures within the next couple weeks.
any questions, just let me know.
best regards
pat
 
So I was curious and did some research on Jet Thrusters:

https://www.hollandmarineparts.nl/jetthruster

According to the installation manual the pump head needs to be install at least 6.5 inches below the waterline + the thickness of the hull and we can call it 7 for their Vertical install.

how far forward could the pump be installed on a CD25 and still be 7 inches below the waterline? I believe the 25 has around a 12 inch draft: Assume both would need to be true: Lightest load possible and/or most awkward load possible(I am not sure what this would be, but assume it is still safe). I would think the hull under either of the dinette seats would be 7 inches under water. Could that even include up into parts of the V-Berth?

Same goes for me as the OP, please don't judge me, I am just looking for information. I was speaking to a C-Brat alum who mentioned how much he enjoyed the boat, but while docking, he said "I hit just about every boat in this marina", which made me laugh, and made me look up this old thread. I know the answer for some will be to get twins, but my question is, how far forward into the cabin is the hull still 7 inches below the waterline while not on plane.

-Troy
 
I have only used the "jet" type bow thruster one time, on a 62 foot Morgan Sailboat when doing a delivery for the Annapolis boat show in 1983, so my reply is dated. It was not a very effective system, and would not move the boat against 15 knot plus wind.

Why has the jet system not been popular? There would be many advantages with a very easy installation. I believe that for most boats it is just not as effective as the in the hull, or external to the hull thruster. At least one C Dory has installed the Imtra 25 EX series external thruster Cost of this system is somewhere in the $5,000 less shipping and installation. It may have some performance effect on the C Dory.

The jet system, purchased in Europe, is over $11,000 US, plus shipping. You might get the VAT back. (includes extra batteries, sinceI plugged in specs for a C Dory 25, and it suggested the 70 pump--which is 24 volts).

Could it be put in a C Dory 25? Probably yes. Would it be a wise investment? Depends, but I doubt that you would recoup the cost. Since the C Dory is a light boat, with no real keel, it probably would be fairly effective...

How often would it be necessary to use? I had one problem docking this last year, in over 1500 miles of C Dory travel. That was trying to get into a slip with a 3 knot current and beam wind of 20 knots both in the same direction. I could not do it--Even If it had the very best bow thruster, and stern thruster, it probably would have been impossible.

I ended up docking on an end tie--which I thought was reserved for "emergency". vessels, and was told it was OK since we would be aboard, and only tied up for a short time. No problem docking with the same wind and current, or getting off, since I was not trying to get into a 10 foot wide slip.,..with limited maneuvering room.

The point is that docking is a skill learned with experience. A good way to practice, put a boat hook, with a fender tied at each end, in the water, --anchor it if necessary if in current. Place this in open water. Then practice coming along side of the floating objects from all angles, in wind and current. No risk of damage to boat, docks or ego.

In a case where there is an absolute necessity to dock in a very difficult situation, there are a few tricks, including spring lines, taking a line to the dock before you attempt docking (using a dinghy), and setting "spring anchors". All of these tricks we used with our 62 foot cruising motor sailor, when getting into very tight dockage situations, including 50 knot winds, and currents. (Single engine, large rudder, and full keel)

The above poster did not put a thruster in a C Dory.
 
I would question whether a C-dory has enough draft at the thruster location for it to be effective. Also, the thruster requires a certain amount of beam for the installation of the motor, propeller, tube, etc. You may have to put the thruster farther back than ideal to get it to fit in the hull (a 25 might be better).
 
We had bow and stern thrusters on our R25SC, they worked great when dealing with narrow fairways, slips and strong beam winds. I aways tried to berth without them but they were great when I needed bailing out!
Our CD 25 is a new challenge in our shared Monterey bay slip with the prevailing 10-20 knot beam afternoon winds, I am new to shallow draft outboard boats but I am learning, so far so good!
 
I had thrusters on my 30' cutwater. Wow, loved them. Docking and loading on a trailer was so stinking easy. I also had a stern thruster so I could move the boat horizontally to. Way to simple to boat. THey were a factory option and installed. However, they occassionally sucked air (bow).
They did leak water inside my boat; just a little.
They did suck in a rope. Same rope from bow thruster to stern! Jammed them both.
The bow also leaked oil.
The prevous owner also stored at a wet slip, so I had to chip away hard growth.
They also have anodes.
All in all, I got a C-Dory to have a simpler boat. I'll be fine without them, I will miss them, but wont miss the extra work and maintenance.
 
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