Jon -
Here is not only the best method for installing a bow hatch, it is also about the least expensive.
Very carefully layout the location, orientation and size of the desired opening. Trace the outline on the deck with a good felt pen. Drill 3/8" holes in the four corners, keeping the entire diameter of the drilled hole within, or to the inside of the layout lines. Then using a good hand held jigsaw, preferably with orbital blade motion, carefully cut along the aft line (if you want it hinged at the back like the traditional CD hatches). Then cut along the forward most line. Be very careful when guiding the saw to not only keep the cut straight, but have a good enough grip on the saw to prevent it from raising up which could allow the end of the blade to bounce off the glass beneath the deck core rather than cut through it.
Now scrounge up some old tires and cut a couple of 2" x 5" chunks out of the sidewall. Take those pieces of rubber and position them near the ends of the aft cut you just made, with the centerline of the 5" dimension stradling and centered on the lines. Get some husky galvanized nails and secure the rubber straps to the deck, using at least three nails on each side of the cut. For safety, you should then go inside the v-berth and bend the protruding ends of the nails over. That will also serve to prevent them from coming loose.
Next, take a 5" length of good 2 x 4 and lay it centered and astraddle the front cut. Drive one husky nail into the end of the 2 x 4 that is on the inside of the cut and right on through the deck. Go inside and bend this nail over, too.
Now you can cut along the two side lines.
There you have it! The heavy rubber straps at the back will serve as spring loaded hinges, and the damn 2 x 4 will hold the front edge of the lid in place. Using this type of latch and hinge arrangement will also allow you to open the hatch in either direction. You can leave the 2 x 4 as is and open the hatch conventionally. Or, you can rotate the 2 x 4 90º (that's why you only use one nail in it) and open the hatch inward. That way, since you are too cheap to buy a windlass, when Cynthia is done pulling the anchor she can simply come back in through the front with little effort.
Hope this helps.
