Stern Thruster

[GarryD]

Hello and happy new year to everyone. I am a UK boater new to the Carver forum. My boat is a 1999 405MY to which I am thinking of fitting a Side Shift ST350 stern thruster, has anyone had experience of these. Any comments greatly appreciated.

[Viper]

I've installed a few, mostly on single screw trawlers where the position of the rudder box made it impossible to install a conventional unit. Customers were very happy with their performance given the large keels they had to push. Haven't been around those vessels for a while so I don't know how they are doing still but in the years I was servicing the those vessels, the units worked good.

It's been a while so they may have changed things some but I was not crazy at the time with the solenoids they were using. They had a high failure rate so I would swap them out for better units right at the beginning. They were just your typical automotive starter solenoid so no issues finding better replacements.

If you contact the manufacturer directly, they will custom make the length of the tube for you which may help in certain applications. All my installations were to the transom not the swim platform, and found the installations to be pretty easy. Have also installed Side Power's external stern thruster (nice unit).

The only issues I have with the Side Shift is the motors and wiring being in the water, and no protection around the props. Other than that, they didn't seem to have a problem moving a 42' trawler.

Curious, why Side Shift? Is it just a price thing? A conventional stern thruster is pretty easy to install, has been around for quite a while, and proven itself to be a top performer. All you have to get past in your mind is cutting a large hole in your transom. If done right though, that should not be a concern.

[GarryD]

Thanks Viper that's helpful. With regards to the standard thruster, although I haven't taken detailed measurements it looks like the stern fuel tank is in the way of fitting the motor.

[Viper]

Is your tank behind the aft bed under the swim platform section? If so, that's the same application I installed an external Side Power unit. The swim platform was toast so it had to be re-cored. Perfect time to add the thruster as I had to cut out the whole top section anyway. Removed the tank giving me access to install the thruster. Impossible to get to the area otherwise. If I recall, I think that was on a 305. Kind of impractical to do just to add a thruster but in this case it was perfect timing because of the platform work. Except for the mounting bolts and wiring on the inside of the transom, all the thruster components are accessible from the outside.
http://www.imtra.com/a45d3762-8ca8-464e-be35-e75e74c033ac/side-power-thrusters-dc-electric-detail.htm

[GarryD]

That's exactly the problem. Can you remember if there is enough room under the swim platform to fit the thruster mounting bracket and cable holes above the water line. I can't seem to find any photos on line showing the stern of a 405 out of the water.

[Viper]

I don't recall, the external Side Power I installed was to be below the water line anyway so I didn't worry about trying to keep the mounting and wiring above the water line but I think the bottom of the platform is out of the water with the vessel at rest. Perhaps another member can confirm. I take it then that you are planning on mounting vertically (to the underside of the swim platform)?

Keep in mind that the ST350 is a 24 volt unit. Unless you already have a 24 volt system on board, this will add an additional complication and expense. You would need to add an additional charger (24 volt), and if you want the battery bank to be charged while the engines are running which is the only way I recommend operating any thruster. Then you'de also need to replace one of the alternators with a 24 volt unit or find something on the market that would convert the current output to 24 volts. Replacing one of the alternators will add the additional complication of charging all 12 volt banks off one alternator and still maintain bank isolation. Can be done but a little more complicated and you loose redundancy of having a second 12 volt alternator but that's another thread.

I'll just ask; do you have a bow thruster? If you do, are the conditions such that you absolutely need a stern thruster? Unless you're trying to get into a real tight spot, fighting current, etc., with some practice using engines and just the bow thruster, you could overcome many conditions without the use of a stern thruster.

Not trying to talk you out of it, just putting it all out there so you have as much information as possible to make an educated decision.

[GarryD]

My berth is very tight with large buildings down wind,with any sort of wind blowing I get blown in all directions and i find my boat very slow to react when trying to berth using the gears shifts. I do have a bow thruster but it seems to have been installed further back from the bow than would be ideal, which reduces the effect. It may also be that I need a lot more practice handling the boat in tight spaces but I would rather fit the thruster than damage mine or someone elses boat. I appreciate any advise you have and have so keep it coming if you think of anything that may be useful.

[Lyndon670]

If I can offer my 2 cents....

My 506 is bigger, taller and wider. It is virtually a sailboat with with the enclosed hardtop. I only have a bow thruster, no stern thruster. I dock my boat stern in, and beside another vessel.

With diesels and a bow thruster, I wouldn't even consider a stern thruster, my wife stands on the swim platform and makes hand gestures to my back up camera. I use a combination of bow thruster and transmissions to make the boat move sideways - and it does exactly that. Port engine forward, stern reverse and left bow thruster - boat moves exactly sideways to port. Invert and it does the opposite.

Your boat will do the same thing.

Save your money. JMHO

[Viper]

Lyndon670 wrote:
> If I can offer my 2 cents....
>
> My 506 is bigger, taller and wider. It is virtually a sailboat with with the enclosed
> hardtop. I only have a bow thruster, no stern thruster. I dock my boat stern in,
> and beside another vessel.
>
> With diesels and a bow thruster, I wouldn't even consider a stern thruster, my wife
> stands on the swim platform and makes hand gestures to my back up camera. I use
> a combination of bow thruster and transmissions to make the boat move sideways -
> and it does exactly that. Port engine forward, stern reverse and left bow thruster
> - boat moves exactly sideways to port. Invert and it does the opposite.
>
> Your boat will do the same thing.
>
> Save your money. JMHO

+1 Lyndon.
I get that it's all about conditions and one's comfort level though.

[g36]

hi garryd i have a 97 405 and the bottom of the swim platform is out of the water by around maybe 8-10 inches or so i could measure it if you need, while at rest. thought about doing the same install curious to know how yours goes please keep us updated