Originally Posted by belizesailor
So, while yes most production cats can be stored on the mini-keels you do still need to handle them carefully and support and secure the boat properly. Most manufacturers will provide you with a suggested blocking diagram.
If the boat was designed to sit on it's keels then the hull
would have been designed and built to support the weight of the boat (by spreading the loads from the keel joint) - not just a matter of bolting on strong keels (keels punching through does
happen on mono bilge
keelers (from hard / prolonged bouncing on seabed) - not often, but enough to be a consideration. No idea what happens on multihulls - but am pretty sure gravity does still apply.........).
To my mind an indicator that the boat was not designed to sit on her keels would be a manufacturer blocking diagram indicating otherwise. As said already, a big difference boat between sitting on the hard
(and having been gently lowered - hopefully!) and the boat being dropped (by the sea) onto the seabed from a foot or 2 - several times as she floats / dries out (try it with an egg
In regard to simply preventing the keels from grinding through, the old style answer was either to have steel
bilge keels, steel
shoes or a dirty great big iron bar - none of which I suspect will be attractive to fit on a Multihull!
.....fortunately the more modern approach is either beefing up the fibreglass with sacrificial layers (different colours helps) or simply gluing on plastic (or alloy) sacrificial strips.
Of course a difference between a boat that takes the ground on a permanent basis and occassionally - wear being a cumulative thing.
Over here we do have a number of cats (and tris) that sit on drying moorings 24/7 - 2 have sunk, but not for keel related reasons (one being 120% of (now) knackered plywood
and the other due to owner not closing the thru hull
after disconnecting the head
- before the tide came back in!.....obviously monos do
also sink for much the same reasons)......will see if I can snap some pics of what folk are doing / not doing at some point.
I would personally take some comfort from the Manufacturer having offered keel bands as at least an option, if not standard (why add 'em if you don't need - or only occasionally).