Bow thrusters and barnacles

[BruceK]

I have a 34 foot sports cruiser whose bow is very light in the winds. I have managed without a bow thruster as I am estuary based and can use the tidal currents to ferry in quite comfortably. There are occasions though when the wind is up that going into a marina for fuel can be quite exciting. However I have always resisted getting a bow thruster simply because cost / use seemed disproportionate for me and more importantly the estuary can barnacle up the works very quickly on anything not self ablating. However my wife is losing some mobility and agility and it may soon come to pass that when docking I end up crewing. However she is afraid of the boat close quarter handling not helped by the times I have struggled in wind. So, do barnacles present a problem for bow thrusters and if so what means of AF is deployed most successfully. Oh and barnacles are a major irritant. I found a way to keep them off my drives with grease and now the blighters have taken up residence inside the drive water intakes choking off water flow. They're diabolical.

 

[Plum]

I have a 34 foot sports cruiser whose bow is very light in the winds. I have managed without a bow thruster as I am estuary based and can use the tidal currents to ferry in quite comfortably. There are occasions though when the wind is up that going into a marina for fuel can be quite exciting. However I have always resisted getting a bow thruster simply because cost / use seemed disproportionate for me and more importantly the estuary can barnacle up the works very quickly on anything not self ablating. However my wife is losing some mobility and agility and it may soon come to pass that when docking I end up crewing. However she is afraid of the boat close quarter handling not helped by the times I have struggled in wind. So, do barnacles present a problem for bow thrusters and if so what means of AF is deployed most successfully. Oh and barnacles are a major irritant. I found a way to keep them off my drives with grease and now the blighters have taken up residence inside the drive water intakes choking off water flow. They're diabolical.

Hi, first, if you normally manage without and only want it for bad conditions then don't scimp on power\size. Second, here on the East Coast barnacles are a problem too but I have just got two years afloat out of my Micron 2 (now Micron 350) with two generous coats on the bowthruster, no barnacals on the prop or in the tunnel and about 6 on the gearbox, probably because that is a bit hard to paint thoroughly. Make sure you degrease and abrade the plastic prop, I applied no primer.

Www.solocoastalsailing.co.uk

 

[Momac]

Travelling into fresh water should kill the barnacles .. and most other marine things.

 

[jrudge]

Just the hull antifoul.

Seems to survive a season in the med ok.

I do look from time to time with a mask and occasionally give it a scrape with my snorkel on

 

[Plum]

Travelling into fresh water should kill the barnacles .. and most other marine things.

Hmmm, in my experience, fresh water may kill the barnacles but it does not make them fall off. How long in fresh water does it take to make them detach?

Www.solocoastalsailing.co.uk

 

[BruceK]

Would a 5hp unit do? (34 foot planing hull, 8 ton sports cruiser)

 

[petem]

Bruce, firstly, I sympathize with you having a wife whose mobility is becoming limited, we're in the same boat. Furthermore, my wife and her mates seem to get distracted when we're backing into our berth....

Anyhow, I've never found that my bow thruster has been overly affected by barnacles. As a precaution you could always paint the prop with some Velox.

 

[Deleted User YDKXO]

Would a 5hp unit do? (34 foot planing hull, 8 ton sports cruiser)

Talk to somebody like Osmotech (Side Power) https://osmotech.co.uk/. They retrofitted a bow thruster on a Broom I used to own many years ago and they have been very helpful recently with a sternthruster problem I've had. I'm definitely with Plum. Do not skimp on the size. The whole point of a bowthruster is to use it when there's a bit of wind or tide so there's no point in buying one if it only moves the bow when its dead calm.

5hp sounds about right to me but get a few opinions. What did the builders fit originally? If you could find out and go one size up you wont be far off

Yes thruster performance does deteriorate with fouling but this seems to be more of a problem in the Med than the UK but its another reason to go bigger

 

[petem]

Would a 5hp unit do? (34 foot planing hull, 8 ton sports cruiser)

4hp standard fit on my 6 ton T34.

 

[BruceK]

Thank you all for your thoughts and tips.

 

[Fusebox]

We had Sleipner SE80 on our Nidelv 28, 3-3.5t boat. Good size for that boat.
We had QL BP900 (twin prop) on our Fairline Corniche. Great thrust from that one.

I would recommend a Sleipner SE100. Plenty power for a windy day, even better with an Optima Red Top (local) battery next to it.
Price difference is not to much, tunnel size same as for SE80, 185mm.
SE80 20,500 NOK (package with everything, except power cables)
SE100 25,999 NOK (package with everything, except power cables)

Considering total cost of purchase + installation, thruster cost/upgrade is definitely worth it.

Edit:
I inadvertently had an error of thought, where I shiftet the entire Sleipner range a notch up.
We had a SP55 on our Nidelv, and thus I'd recommend a '80 sized thruster for your boat. As stated earlier, it is in windy conditions you need it mostly, so peace of mind with proper hardware installed is almost priceless.