My Nacra does not have inspection ports in either hull. Do I need them? I would really hate to put 6-inch holes in my hulls if it isn't necessary. Any thoughts would be appreciated.

Along the lines of let sleeping dogs lie, I would not put any additional holes in any boat unless they are needed to repair the boat.

Some folks do put them in so they can put the port bags in them to carry additional gear.

I put ports in my H16 and my TheMightyHobie18 came from the factory with them. I use them for gear storage (port bags) and for drying out the hulls. The extra holes allow for great air cirbulation (especially when you leave them open while trailering). Both my H16 and my TheMightyHobie18 had no water leaks.