This thread has been an ..... interesting ..... read, but not for the reasons I had hoped for. (Smack, that was quite possibly the longest and most entertaining "marketing" post I've ever seen!) I was hoping to learn something about steel boats and their qualities but that dream died many pages ago. I DO NOT believe for one second that steel is infallible. Brent's claims about shrugging off reefs and rocks with only scratched paint are ridiculous. I was on board the USS Carl Vinson back in '90 going through a seriously major storm when the ship slammed into a wave. After the damage control crews cleaned up the mess, we all got to see the damage caused to the foc'sle. The main beam in the stem was buckled and plate metal bulkheads much thicker than the skin of a Brentboat were dented from the where the caps to the hawse pipes blew into the space and ricocheted around, all from slamming into a wave. So Brent, I don't believe your claims one bit.
I think steel has it's place as a material of choice but I don't believe it is the ONLY choice. I've seen much advice given and several books mention that steel hulls are a good choice for high latitude sailing but what about the more temperate areas? I'm not ready to discard a steel boat just yet but from everything I've heard, read, and experienced, it seems to require much more attention to corrosion than other materials. I've also read that condensation can be a problem unless it is insulated. Are they typically insulated only from the waterline up or are they also insulated below the waterline? It seems to me that sprayed insulation would make inspection and repairs problematic, especially while underway.
Check out the law of mechanical similitude for a comparison between large boats and small ones in terms of the relative strengths .The bigger the boat the more marginal the strength becomes. Small steel boats are grossly over strength, super tankers marginal. An example would be the test I suggested to Smack. Take a tin can, sealed ( a condensed milk can with the holes soldered shut would work) Stand waist deep in water and try making a hole in it with an aluminium baseball bat . Now imagine a similar sized bat to can ratio on a super tanker. You wont make a hole in the can, no matter how hard you try, but the super tanker hit with a much larger bat that itself, would break up quickly. A small steel sailboat can pound on a lee shore for weeks without serious damage , but a super tanker in dry dock will break in half if the supports are not perfect. Shipyard workers can confirm this.
That is how the law of mechanical similitude works.
I have zero condensation inside my hull, despite living aboard her full time for 29 years. Spray foam eliminates it completely. It is however very important o heavily epoxy the inside, before spray foaming. Foam does not protect it reliably. Many commercially made boats ( Foulkes Fehr, Amazon ) have zero epoxy under the y foam, and rust from the inside out , sometimes rather quickly. Anywhere I have dug out sprayfoam, in my heavily epoxied interior , to install thru hulls, deck conduits, etc., the steel under it has been in perfect condition.
Spray foam should be carried to the floor boards. Some fish boats were foamed right down into the bilges and the foam acted like wicks, drawing bilge water high up, causing serious corrosion. Hulls and keels made out of only 1/8th plate doen't help any. You need a place for the water to drain out of the foam. Leave the foam out a foot either side of the centreline, and in any engine compartment .
On deck, the biggest maintenance problems are paint chipping of outside corners, Flat surfaces are far less problematic. If you have corrosion problems on flat surfaces, the paint is not thick enough or the steel under it was not clean enough ,before painting. Trimming al outside corners On a steel boat with stainless, can reduce maintenance by 80%
For marina queens, and "occasional use" boats , fibreglass is far less maintenance, than a steel boat. For full time, hard use, where a plastic boat would have cleats worked loose, things breaking , and deck leaks to constantly re-seal , workboat priorities prevail , and a steel boat becomes far less maintenance.
Bob Perry, an indisputable expert on fibreglass, knows next to nothing about steel boats. Nor does Smack. Neither has any hands on experience building, , cruising in, or maintaining a steel boat over many decades .
Best get your steel boat info from those who have built or cruised in one successfully, over decades. Otherwise you are getting only misinformation spread by plastic boat salesmen.
To see what a small boat can take , check out the" Gringo "photos on cruisers forum. That kind of impact would have cut a much larger boat in half.