Saros' engine is a reliable and frugal 1.8 ltr BMC diesel (I think). The
engine compartment is well soundproofed, and at moderate speeds, the boat
is very quiet. I have frequently surprised anglers with our stealthy
approach, who have to hurriedly pull their lines out of the way because
they haven't heard us coming.
The engine originally was fitted with a 'wet' exhaust system, which was
fine when it worked, reducing exhaust smoke and noise significantly, but
because it relied upon sucking dirty water from under the boat, was prone
to blockages in shallow, muddy water. So after some years, we decided to
remove it and fit a 'hospital' silencer, which is still commendably quiet,
if a little more smokey - but nothing significant.