Re: [Amel Yacht Owners] Bow thruster

Alexandre Uster von Baar

Good morning Jose,

Did “Amel” recommended to add a 3rd seal???

Could you please send me picture of the “system with a clamp” that you develop? I was thinking of a similar device.

I own my vessel since 2012 and the bow thruster also start leaking after 1 year of use (even after being serviced by Amel Martinique with a new bow thruster foot).
Consequently, I checked the bilge near the forward head every time I sail and I also installed a high water alarm and bilge pump.

Every year when do the overhaul, the foam look good (but I still change them). I often suspect this is coming from the seal.
It seems the problem start if I accidentally motor over 2.5 kt (bow thruster down) which is some time unavoidable with 2 kt current.

I was also wondering if this was because of the rigging which I have not redone, but I just did the overhaul 2 months ago (and not the rigging) and no leak now even in 9ft seas.

My latest thought is the “contact cement” which could degrades after 1 year, but I don’t know for sure.

Our hull number are not far apart, may be there was a slight different design at that time.

Sincerely, Alexandre
Club Nautico de San Juan, Puerto Rico


On Tue, 6/7/16, jvenegas@... [amelyachtowners] <amelyachtowners@...> wrote:

Subject: RE: [Amel Yacht Owners] Bow thruster
To: amelyachtowners@...
Date: Tuesday, June 7, 2016, 9:48 PM


Joel,I checked in my boat and as you
mention, there is no draining tube out of the bow thruster
compartment and that explain why we have been frustrated
drying up with a sponge the water that regularly collects
from the leaking bow thruster seals 
Since I bought my boat, I have
serviced the bow thruster and replaced all seals in my SM278
several times (5 in 6 years) .   In all cases a leak
developed around the lip seal soon after service. In fact,
just after I bought the boat, the previous owner told me he
had just serviced the thruster.  I was really shocked when
I found the the compartment filled with water after just one
overnight from Florida to Savanna.  I proceeded to replace
all seals following AMEL instructions and the leak stopped
for about a year.  That was the longest period without a
leak and the start of my saga.
For the second to last service I
spoke with AMEL in France and was recommended to add a third
foam seal to the thruster assembly but that only eliminated
the leak for a few weeks.  As I was about to cross the
Atlantic, I developed a system with a clamp that I secured
around the shaft and pushed down to create a good seal.
 That worked well for the one year trip from Boston to
Spain, Caribe, Santa Marta, Fort Lauderdale and back to
Boston.  Although my solution is good and I recommend it to
anybody doing long crossings,  as I returned to Boston it
became a nuisance to have to clamp and unclamp the thruster
every time we left the marina.  So, taking
advantage that I was  giving Ipanema a new bottom paint las
week, I  serviced the bow thruster system for the last time
and carefully cleaned the surfaces and changed again all the
foam and lip seals and I added two extra turns to the top
screw to bring the motor up as much as It was
possible. Sadly, on my return trip from
Glaucester to Boston under moderate waves I noted again a
leak around the lip seal (brand new) in spite of the fact
that I had to add manually quite a bit of extra tension to
the cable in order to align the holes to pass the securing
Do you or
anybody in this group have an idea of why is this leak
persisting in my boat? 
I believe that the bottom two foam
seals should be enough to completely seal the system and the
lip seal should only work during the short period of time
deploying or retracting the bow thruster.  So if they are
not preventing a leak, it must be that in my boat poor
alignment between the sealing surfaces may have developed or
becomes important when tension is added to the cable to
increase the sealing force.
Any suggestion about how to fix this
problem.  It must not be very common as few people complain
about it in this forum, but it may have been enough of a
nuisance for Amel to add the tubbing/valve to isolate and
send the leaking water  to the main bilge. 
Has any one retrofitted such a
tubbing/valve in SM2K earlier than the redlined
VenegasIpanema SM2K 278 Constitution
Marina, Boston MA

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