Yachts & Boats

I am David Duong, I am an associate marine surveyor for the Society of Accredited Marine Surveyors and for the Bureau Veritas. I will be posting here stuff related to my job which you may find interesting.


Mon nom est David Duong, et je suis expert maritime agréé par le SAMS et le Bureau Veritas. Je partagerai ici un certain nombre d’éléments relatifs à mes activités nautiques
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Hello world

So you think you had rough seas ?

Beneteau 473, 2001. Another Ford-T of the yacht industry.

This jacuzzi is to be found in front starboard hull of the Lagoon 570 pictured below. The owner basically took off the bed and installed the bath instead. It’s unusual but pretty cool.

Lagoon 570, 2005

You’ll need an hydraulic pump such as this one:

The pump is used to push an adapted bracket (yellow) through the strut, pushing the old bearing out (no need to remove the shaft).

Old bearing coming out:

Done !

The new nearing is fitted using the same tool but the other way around.

As a reminder, max. play accepted for a shaft inside its bearing shouldn’t be more than 1/2 a millimeter. Any more than this, replace the bearing. 

The above picture is a leak of raw water spotted at the exhaust elbow of the port engine of a Leopard 39, 2012. Engine had 500 hours:

Same problem was spotted on the starboard side (engine had 800 hours on this one). 

This is the culprit:

leaking exhaust elbow

Once cleant Up, you can clearly see a crack at the junction between the plate and the hosing:

cracked mixing elbow

We managed to weld back the port one:

The starboard one was totally rotten, stainless was cracked internally up to 1 cm within the tubing, so a new elbow was fitted (these elbows are sold for roughly US$180).

Can this issue be considered normal wear and tear, or do you think Yanmar uses cheap stainless steel ? We understand exhaust fumes and waters are corrosive, should 500 hours be considered normal span life of a stainless steel part ?

Those get worn after time.

Like these ones:

worn propellers

Notice how the central hub got ovalized. If left on, this will slowly damage the main shaft seals, and will let sea water enters the whole leg, emulsifying the gear oil into  what is commonly called “mayonnaise”.

The Fort T of yachting, hundreds of hulls built for more than 10 years, and still a best-seller