I am about to cut out the whole fiberglass deck from my boat. I
remember that was a very dusty job when I cut an area of the floor
using a circuit saw and a grinder (with a cut off wheel) even with a
shop vac pointing at the cutting area. I would like to find a less
dusty way of cutting the floor using a power tool.

I know I will not be using a grinder (with a cut off wheel) because I
cannot see how I can keep the dust down using it.

My circuit saw doesn't have a dust port. Would the result be much
less dusty if the circuit saw had a dust port? If it will be less
dusty with a dust port, it will be my first choice because I can cut
very straight using a circuit saw. But I doubt it because I have a
feeling that all the rotary tools kick up a lot of dust and will be
hard to control dust.

Is a jig-saw much less dusty? I know I would have a hard time using a
jig saw to cut at 45 degree angle. But this should not be a problem
because I am cutting at a 90 degree angle anyway. I may have a hard
time to cut a straight edge using a jig saw. But I think I can fix
this by using a straight wood board to guide the jig saw.

Is a reciprocating saw less dusty? Then I can use it to cut at any
angle, like what the guy in ShipShape TV used to cut a hole on the
floor of a boat and keep the cut edge at a 45 degree angle. But I
have a feeling that I would have a hard time to keep the cut edge
straight using a reciprocating saw.

Any other better power tool? I welcome any suggestion and experience
that people want to share.

Thanks.

Jay Chan