Bow Thruster getting covered in growth

[mf755wahoo]

We have a Quick bow thruster - very useful for the parallel mooring we have to do at our marina berth.

At the weekend activated the thruster and got an immediate, unwelcome, change in sound of the motor, without any thrust happening.

When we anchored up out of the marina I took the opportunity to go over the side and have a look at what was going on. I found that the aggregation of marine life (weed, algae, barnacles and small mollusc attaching to the housing, propeller and actual tunnel) had caused enough of an obstruction that a couple of the fins had broken off. (see attached pics - sorry for the quality!)

The boat was hauled out by the marina in May 23 for hull pressure wash and engine service. We didn't see the boat when it was out (is on a marina berth all year) and the marina put the boat back in, without saying anything about the condition of the bow thruster.

In May 2022 we had instructed the marina to anti-foul the boat and do a clean down of the thruster.

Am I being a bit 'touchy' given that I think it would probably be in the Marina's 'Code of Conduct' to maybe highlight possible areas of concern when they get a boat out and give it a clean? Is that what others might expect would be done?

Also - if the bow thruster area was cleaned down in May 2022 would it be reasonable to expect this amount of marine growth to have accumulated? I am now wondering if they ever did the work given we never see the thruster.

So - obviously we need to have the propeller replaced - but what else can we do to protect against growth season to season? Anyone with a boat in the water all year what do you do?

Thanks in advance

         

[Zanshin]

I've kept my boat in the water year-round for 3 years and this past season I used the bowthruster to assist in doing a tight turn in anchorage when the same thing happened to me. The noise changed and no thrust. I believe that the shear pin separated and the bowthruster channel looked like a marine park. I'm on the hard now and will clean the bowthruster channel and replace the shear pin. My bowthruster looked worse than yours, I couldn't see the light on the other side when looking through.

A good yard will do what you tell them to do. No more, no less. A bad yard won't even do that. I don't expect the yard to note things like an encrusted bowthruster, rusty streaks off the keel, loose rudder, and so on; and that means I've never been disappointed

[MalcolmP]

I sympathise, had the same happen in the Mediterranean when we returned to our boat in early September. IE no power...You do need to antifoul the blades and the tunnel. I was though able to swim and clean up the blades and tunnel enough with a scraper and wire wool enough to get it working again OK. We are only on the boat for a few weeks, so that will be fine until we haul out. I hope...Malcolm

[loredo]

Something similar happened to me this year too!  Only my BT and tunnel were antifouled and "almost" clean. When I changed the props the old ones seemed very bristle. My BT has two counterrotating propellers. One of them first lost one blade. Next time I used it all blades broke off.  Luckily I was able to get replacment props before Quick closed for vacation this summer. I replaced them both with the boat in the water.  Wasn't too difficult, it took me maybe 30 minutes. The one thing worth to mention is that Quick changed the propeller design entirely.  The old one were four blades while the new ones now are five blades. Most of all the stuff the props are made off is different.  The old ones were some "cheapo" plastic while the new ones are some sort of glass fibre (carbon??? dunno..) reinforced plastic.  Oh, it seems to me that the new five bladed version provides a bit more thrust too.

Added on edit : next haul out I'll antifoul the BT with Propspeed! 

I don't know when Quick changed the prop design. Last year / years ago???

[ales]

It is normal… Bowthruster is like a small cave… ideal for growth. I do haul out every two years and in between I clean it in the water. Not perfect but it does the work

[mf755wahoo]

Good Morning All - many thanks for the comments and suggestions 👍😀
Maybe I’ll get my weight belt and scuba gear out and see about give the area a good clean while the water is still bearable! If we can then do the prop change all well and good, or we will get it sorted when the engine is serviced next Feb