The gratings are custom fitted to the boat. Thus you have a lot hands on shaping of the wood.
But gratings do help keep your feet dry, by allowing the water
that board the boat to run off faster and you don't need waders to get around in the cockpit
IF you find a grating that is too large for your boat, you can always trim it down to size and have it looking good.
But unfortunately there are no wood stretching machines that can make boards longer. So if you find one that is too small. Let someone else purcase it.