Hello all

You are a group with a lot of technical interests and knowledge.

Boats - for a vessel with a single screw and about 500HP, or a
twin-screw vessel with about 1000HP (500HP each engine and gearbox
drive)...

Some have a/two straight-6cylinder engine(s) like the Cummins K19(M?)

Some have a/two Caterpillar 3412 V12 engine(s)

Why?

The straight-6 would be - cheaper? simpler?
The V12 would be - ... ?

Thanks in advance is you can help take this curiousity to its
end-point.

Regards,
Rich S