Crunch Crunch

[O C Diver]

Took a short 3 day cruise to do some kayaking. Coming back to the marina decided to stop at the pump out dock. Swung the boat around and bumped the bow thruster to push the bow over. Crunch crunch! WTF! Got the pump out taken care of and went on to my slip. After squaring the boat away, pulled out the dive gear, tools, and spare parts. With everything assembled on the swim platform, went for a swim. Here's what I found:



40 minutes later the spare set had been installed and the thruster was back in business.

Here are my takeaways.

1. You never know when you'll loose your bow thruster. It didn't quit; it lost 60% of its power and made a god awful noise. Didn't use it after that for fear of making it worse. Don't know what went into the tunnel, but there was 5' of water under the keel.

2. Learn to drive your boat without the thruster(s), you never know when you will loose them.

3. Spares! It's all about spares. For those of you who don't stock spares, how long do you want to be without your bow thuster? If you're cruising, how long do you want to wait for parts to be flown in? Even if you can't install them yourself, if you have the spares, any hull scrubbing diver can do it for you.

4. Tools! Have the tools, if you think you're going to do it yourself. Someone mentioned that they could have someone talk them through the repair over the phone or interner. If you're going to keep these spares on board or have them flown in, make sure you have the tools to do the install. While the tools for this job weren't special, a long extension and a 3/4" breaker bar was the difference between happening and not happening. Can't emphasize enough, duct tape, WD40, pliers, and screwdrivers aren't going to get it done. Even if you can't do it, if you have the spares and the right tools, someone else may be able to fix your boat when you're broken down in paradise.

Ted

 

[gaston]

There one thing I have learnt /learned with boats that is money fixes everything

 

[Capt.Bill11]

I'd recommend putting Prop Speed on your new replacement blades.

 

[tedted]

Being new to trawlers but many years a sailor There's two things I've learned,
1. Tools. You cant have too many tools.
2. Back and fill. The art of trawlering with a single screw. (still learning that)
I've learned not to not be humiliated when I back up for a quarter mile because the cross wind cannot be overcome...lol... If I were rich and famous, they say there's these thruster thingies. Boy they'd be nice....

 

[healhustler]

Good post, Ted. Haven't heard of a thruster going quite like that. I'll make sure to pick up the breaker bar and extension next trip to Harbor Freight....cheap, but perfect for those rare occasions. Still curious though...about what went through the tunnel. Maybe it was a Barracuda.

 

[slowandsteady]

My challenge when I back into the slip is to not touch the bow thruster. Sometimes I don't touch it, other times I have to.... just a little.

 

[O C Diver]

I'd recommend putting Prop Speed on your new replacement blades.

Propspeed is based on significant water flow over the surface throwing the barnacle spat off. Don't think I use the thruster frequently enough for a long enough period to make that happen. The blades look like they will hold bottom paint though.

Ted

 

[HenryD]

Ted,
Sorry to read. Not sure what nailed the thruster and I hope you don't find it again.
On land it took me an hour to change a blade. If I tried to do that on scuba - I better have two sets of tools (I am going to drop one for sure) and I better have two scuba tanks.

 

[dhays]

No way I am going in the water to look at my thruster. Too damn cold.

 

[wwestman]

I have the dive gear on the boat BUT it will take a lot of convincing to get me into 50 degree water.

 

[O C Diver]

That's what they make wetsuits for. Wouldn't have any hesitation doing that job in 50 degree water with a 5mm wetsuit with hood gloves and boots.

Ted

 

[wwestman]

I wear a 5 mil in 70 degree water. For this stuff I will need at least 10 or 12. And a LOT of lead.

I admit I am a whimp. Too many years of diving in the Islands.

 

[gaston]

Needing a wetsuit is a good reason to keep out of the water

 

[Insequent]

Propspeed is based on significant water flow over the surface throwing the barnacle spat off. Don't think I use the thruster frequently enough for a long enough period to make that happen. The blades look like they will hold bottom paint though.

Ted

I antifouled a week ago, and this time we put propspeed on the thruster blades. Previously I had put bottom pint on it, which was not all that good in performance.

There's no reason you cant run the thruster for a little bit every time you anchor, or after you dock (if it wasn't used for docking) just to spin it up and let the propspeed throw off the growth.

 

[Capt.Bill11]

Propspeed is based on significant water flow over the surface throwing the barnacle spat off. Don't think I use the thruster frequently enough for a long enough period to make that happen. The blades look like they will hold bottom paint though.

Ted

I've been using Propspeed on my thruster blades for years. Works fine.

You can just hit your thrusters once a week or so. Or I find that yes stuff will grow on them but most of it will spin off the next time you use it.

It's not just about spinning off the spat. Barnacles may grow up on it but they are not necessarily stuck well to it.

 

[dhays]

Needing a wetsuit is a good reason to keep out of the water

+1

 

[MVDarlin]

Hmmm. Don't have a bow thruster, I use twin screws, but looking at prop condition it appears you are in a hot harbor with excessive corrosive galvanic action. I had a similar problem in Paradise Village, Puerto Vallarta, Mexico. Ate up a $10,000 set of props in a couple of years. Turned to swiss cheese. Maybe you need a galvanic isolater. I now store my boat on the hard in the off season. Another good saying "an ounce of prevention".

 

[Ski in NC]

I have a sidepower single prop unit that looks just like one of those props. When I installed the thruster and launched the boat I felt like it was pretty weak and I slapped myself for being stingy on spec'ing it out. Also noisy. A few months later the water warmed up and I dove the boat. One blade missing off the prop!!! How long had it been that way? Pulled the prop and there were barnacles on the busted blade root.

I think I sucked up debris on initial launch and broke it then. Lift well was in the river which is full of floating crap. Never heard the "crunch", but it was a busy time.

So I have proven that the thruster will not destroy itself with a missing blade!!! I ran it for months that way.

So the prop with the missing blade is now my spare.

Got a new prop on and whoa what a difference. Quiet and a good bit more power.

I try to run mine at least once a week to shake off barnacle spat. That technique and bottom paint have not proven very effective.

 

[rwidman]

We are often advised to carry spare parts and the tools needed to replace them and basically, that's good advice.

The problem is, you never know what is going to break on your boat and as a practical matter, we can't carry spares for every part on our boats. We don't have the storage space and cost would be prohibitive. The best we can do is carry spares for the parts most likely to fail. Impellers, belts, filters, etc. A prop perhaps.

I was cruising and had a transmission oil cooler fail. Who would have thought that would fail? I had a battery combiner fail.

A lot depends on where you cruise and the availability of parts. I was able to have the transmission oil cooler shipped overnight for an extra $100. Compared to the $75 per night at the marina, that made sense to me.

There are many factors and no list of spares fits all of us.


BTW: My diver services the thruster prop and anode so I'll know if anything is wrong.

 

[North Baltic sea]

Crunch crunch, I thought that the debate was a breakfast cereal.

I am sorry for you loss. I'm with you completely agree that the platform must be able to drive without toys bow / stern thruster. of course, they are so easy to come ashore, but always with honor, I believe skipper who knows how to command the base without toys. I have had the NT for a few months, and even a little bit to learn. old boat had two engines and humbly obeyed the captain's will.

thank you OC driver to share this experience.

 

[Ski in NC]

I ran my single engine boat for a few years without thruster. That was a dang good education. I learned how to handle it, learned what to not even try, and learned that I wanted a thruster!!!

 

[O C Diver]

Hmmm. Don't have a bow thruster, I use twin screws, but looking at prop condition it appears you are in a hot harbor with excessive corrosive galvanic action. I had a similar problem in Paradise Village, Puerto Vallarta, Mexico. Ate up a $10,000 set of props in a couple of years. Turned to swiss cheese. Maybe you need a galvanic isolater. I now store my boat on the hard in the off season. Another good saying "an ounce of prevention".

No, clearly sucked something into the blades. This wasn't galvanic corrosion, these props are a plastic material.

Ted

 

[ranger58sb]

Propspeed is based on significant water flow over the surface throwing the barnacle spat off. Don't think I use the thruster frequently enough for a long enough period to make that happen. The blades look like they will hold bottom paint though.

FWIW, we've had decent luck with Barnacle Barrier on our underwater hardware...

-Chris

 

[bilge53]

I ran my single engine boat for a few years without thruster. That was a dang good education. I learned how to handle it, learned what to not even try, and learned that I wanted a thruster!!!

Ditto. Our MS1 was a good learning experience after 40 years on sailboats with nice keels. When we bought our current boat which has significantly more windage I budgeted for a new large Sidepower bow thruster. When you need it you need it.

 

[LongJohn]

Which is more reliable; the thruster or the second engine of twins? Anyone have any actual data on that question? I'm thinking that I need to practice without my thruster ( love it) as often as I would docking a twin screw vessel with one dead engine.

 

[bilge53]

Not sure I have a good answer but along the same lines whenever docking or doing any anticipated maneuver that will/may require a complete stop I always do a momentary shift to neutral to make sure I can get there and a cable hasn't slipped or some other un-known calamity hasn't occurred while motoring the hours preceding. Re: the thruster; if it is a foregone conclusion that it will really be required I always turn it on and bump once in each direction...just in case.

 

[CaptTom]

2. Learn to drive your boat without the thruster(s), you never know when you will loose them.

... or when you'll be running a boat that doesn't have one.

On one boat I run that has one, I have to guard the switch when approaching the dock to be sure no-one turns it on. I'm a bit of a purist, and it's a twin screw. On a boat with a single, I won't argue about turning on the power switch, but my goal is still to dock the boat without touching the thruster controls.

 

[O C Diver]

FWIW, we've had decent luck with Barnacle Barrier on our underwater hardware...

-Chris

Yes, I'm using that on my prop and skeg this winter, with great success so far.

Ted

 

[markpierce]

I use bottom paint on the thruster.



Thruster is used every time the boat is taken out, if just to see if it's still working and to throw off any grass. Saves wear and tear on transmission and propeller shaft too.

 

[Blissboat]

O C Diver wrote: "2. Learn to drive your boat without the thruster(s), you never know when you will loose them."

Strongly second that motion. Plus, if your thruster fails, it will likely announce the news at the most inconvenient moment - like when you really need it.

Even if your thruster never fails, knowing how your boat responds without it is vital. If you boat often enough, there'll be times when the wind and/or current will be too much for the thruster, and you're left with your main engine(s) and your wits. Try docking and getting under way in those conditions without touching the thruster, and make mental note of what works.

With every boat I've ever owned or run, I learned more about its handling characteristics in fifteen minutes around the docks on a windy day than I had learned in the preceding six months or more.