My comments pertain only to the twin keel boats such as those built by the former Westerly company of England
Having owned two with iron keels I admit at first I was suspicious. I've found that iron keels, all four of them on two boats, to have only one 'temporary' disadvantage. Certainly no 'legion' of disadvantages.
The one case was a pair of iron keels that has been sheathed with fiberglass
. Exactly the wrong thing to try as a fix.
Once stripped and the keels properly cleaned to grey metal, treated primed and painted mine have shown no problem with rust etc. The trick is to clean to grey metal and then use Pettit Trailer Coat also called Rust Lok and in Europe
it's called Screw Fix. That bonds with the metal and expands/contracts with temperature changes. It doesn't flake or chip off. Once the Rust Lok is applied then normal priming and antifouling follows. In short proper maintenance
just like anything else.
In the case of twin keels the use in supporting the boats when the tides are out is correct. Lead probably can't do that day in day out for decades. Hitting a bottom though is not nearly as likely as with single
keeled boats. Twin keel boats sail faster when more upright and are usually shoal keeled. We heel them as little as possible to gain the most speed not the other way round. They also produce a longer 'wave' and not being displacement
boats the formula multiplier is more accurate at 1.4 than 1.34. Besides no one plows through reefs
anymore..it isn't eco-friendly.
I would far rather have a well built, properly maintained seaworthy
iron keeled boat than for example some of the single
lead keeled boats whose list of problems are in fact legion.
Problem you will encounter are osmosis
, difficulty tacking in very light airs, and not pointing quite as high but better than full keel boats.
Hardly what I'ld call 'legion.'