What kind of popularity do aluminium boats enjoy over there?

In Finland it looks like aluminium boats (usually ranging from 4 meters
to 7 meters) are gaining wild popularity. I would attribute this mostly
to durability and easy maintenance. The two most popular boat brands
are reported to be Buster (only aluminium hulls) and Silver (mostly
aluminium hull boats with glassfiber deck/superstructure).

Silver just introduced a rather unusual boat, the Moreno which is a 21
feet day cruiser. (Or at least they claim so - I'm not sure if it has
berths!) Looks sort of weird...
http://www.silverboats.fi/index.php?lang=eng

In the US I know there are some models which have aluminium hulls and
jet propulsion. It's a bit funny that such a boat type is unknown in
Finland, given our notorious, shallow waters with lace-like patterns of
little islands, submerged ridges, rocks and stones. Our largest lake
system has an average depth of 0.5 meters (2 feet)! I suppose jet type
propulsion is not just too efficient for our typical power ranges, even
though it would be a safe bet for our waters. (Our aluminium boats are
usually powered by outboards between 20 and 150 HP.)

Is there some good literature available on aluminium boats? I know
there is the metal boat book by Bruce Roberts and some books on
aluminium boatbuilding... But what is lacking could be maintenance
guides for aluminium boats and literature concentrating on small
aluminium boats. Perhaps they are just a local peculiarity in Finland?

Risto