Light grounding, Swan 411
Hello all -

Recall earlier this summer I hit a rock at low speed. The boat was hauled out today, and it appears that my hunch, and Lars' words, were accurate - that being that no real damage seems to have taken place. Attached are a couple of photos showing the front bottom edge where the first impact was, and also the trailing edge - I think the trailing edge wear is ordinary and did not come from the rock. Anyway, based on everything I will just have her faired and add a few layers of paint (I had just had a big job done on the bottom last winter, and there were probably 3 coats of paint on her, over 5 coats of epoxy - but in this area of the bottom, we really don't need all that).

So, here's at least one confirmation that one of our great S&S boats can take a little strike on a rock, as long as she is not going too fast, and does not hit so high up that the boat dives, or stops. Of course, it's always prudent to have a look when conditions permit, but since they don;t always permit, you need to have confidence in the structure. The other lesson I relearn and try to take to heart always is - when you are in close quarters, even in known waters, keep your speed down. There's not a lot to be gained by going fast - and sure a lot to be saved by going slow if anything does go wrong.

Geoff

Corazon, Swan 411 #41

Geoff,

I see the grounding problem. Its electrical. You might look into how Nautor set up the lightening protection systems for the Swans.

If your model is like the 431, the large stainless plate at the bottom of the keel is very instrumental in this system. As they designed and implemented the lightening protection systems, the electrical grounding of the vessel requires a large metallic surface area in contact with the water to help bleed off electrical potential differences between the water and the atmosphere. These differences can build up when there are storms with lightening involved.

It would be safer to have the SS plate along the bottom of the keel exposed and make sure the mast and through hull fittings are electrically connected to it.

If you have seen the "charge dissipater" brush-looking devices on top of some masts, they are recent add-ons to these lightening protection systems. These brushes make the bleeding off process more efficient.

I mention all this because it looks like the SS plate is painted over on your vessel's keel. This is about safety.

My best,

Kendall

Kendall -

I had hit a rock this summer, and we had discussion on the list about possible damage - that's what my post was about. You bring up a good point however, on the electrical system. My boat still has everything bonded together and down to the keel. i am unaware of a separate plate on the keel on this boat. I am not sure if there was one that leaving it unpainted would help much in the long run (corrosion/biofouling), and I am not sure of the electrical conductivity of the paint - but I will explore these questions on and off this list and see what we get.
Geoff

Corazon Swan 411 #41

I have hit numerous rocks while sailing in the Baltic, particularly bumping into and out of Kuresaare, Sareema, Estonia. The keel is made of lead and it seems to have survived these bumps without any sign of movement. I simply faired it off, antifouled and set off again in search of another rock!

Anthony Wotan 411-40