[Anonymous]

Hi everyone – I am a relatively new member, having purchased a 2007 37 Cruiser last summer (moved up from a Sadler 26).

I have a few questions regarding protection from galvanic and stray current corrosion. Having looked around the site for related posts I’m not sure I have an adequate answer yet but if I’ve missed something please forgive me! I am new to saildrives also.

I have a Saildrive 130S on a VP D130B. The only anode is in front of the Kiwi Prop and was replaced last July when I purchased the boat. It appears to be lasting fine so far, having spent all of her “parked” time plugged in to shore power. I’m not aware of any particular electrical/corrosion problems yet but have been considering whether or not I ought to fit a GI (I put one on last boat for marina shore power/corrosion protection – her only anode was on the propshaft and lasted well, but in a different marina).

Is my saildrive isolated from the engine? Can I easily verify this with a multimeter?

Is it usual on a boat like this to not have a hull anode? I see from other posts that many of you do have hull anodes.

Do these boats come from the factory with non-bonded through hulls? (I’m afraid I’m not at the boat and have started this thought process without being able to physically check).

Did Bavaria make these boats (in 2007) without bonding the shore power earth to the DC negative? I believe the RCD rules about this changed around 2012 to force all earths to be connected to DC negative from then on, although opinion on the wisdom of this is still divided.

Am I correct in thinking that if (a) my saildrive is isolated from the engine, and (b) none of my through hulls are electrically connected, and (c) my AC earth is not connected to my DC negative, then there should be no indication for a galvanic isolator, or in fact a hull anode?

And the anode on the foot of the saildrive leg should be sufficient to protect the casing?

Apologies for so many questions, but I know the answers are out there! So many thanks in anticipation….

David
Dunedin

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