Plywood Tank Floor Fiberglass Layup?

[CaptScottNC]

warthog,
I appreciate your response. Where haveyou found is a good place online to get glass from? will be putting in an order today. Just need to decide what glass and how much I should get for the plywood floor beneath my tank. And what I need to replace the glass on the underside of my hatches when I recore them. Have any input on the proper glass for building up layers under the hatch and plywood floor of the tank? The repairs that were done before had some rovin woven plastered underneath the hatches in a rather ugly way.

any suggestions on how many layers and what weight cloth for my hatches would be very helpful. I have some books coming on fiberglass and gelcoat work but need to get an order in today hopefully.
Thanks in advance,