I'd say trim away!  As long as you can get a good deck-to-hull fit, that excess is just that, excess... cut it off!  Cutting it after installation isn't difficult, but strapping it down can be a chore, especially with a large overhang.  I pencil'ed the edges of my deck when dry-fitted and cut it close before epoxy-ing it in place.  The left-over was easy to remove with a hand plane.

Good luck,

Larry

I would need more info--What are we building? CZ

I would trim.

If you have too much overhang you can have difficulty strapping the deck on a curved deck. with too much overhang you could pull down the edges and lift the center.  If you can trim off 2" and still have a 1" overhang then trim off the edge.

Be careful using jig saw on curved deck.  Some have suggested cutting from underneath to protect the hull.

J

Thanks Gents, much appreciated. And to answer CZ's question, I'm building a Chessie 16LT.

Thanks again,

John

After dry fitting the deck to the hull, I was amazed at how hard it is to bend that plywood down to the shear clamps.  I wondered how hard it was going to be to get the thickened epoxy on, epoxy the underside, place it,hold it down, nail it, etc..... I wondered about forming the deck via steaming and decided to try it.  Made a strongback with curved forms(14.75" radius) every 10", built a steam box 16" x 30" by 96" (almost entirely from pink styrofoam) and strapped the deck to the form.  Applied steam until one of the hip brace pieces in the steam box could be bent by hand.  Now the foredeck lays on the bulkhead and deckbeam, requiring no bending force at install.  I'll do this with the rear deck as well, on different radius forms.  I'll be able to pre-trim the deck to about an 1/8" overhang before install.

Carlo