Porthole Glass Replacement

Good day all!

One of our port holes started leaking and when we took it out to replace the rubber seal, we noticed a crack in the glass.  We now need to replace it and we're wondering:
- has anyone done this before?  if so, where did you purchase the replacement glass from?
- we're currently in the Chesapeake Bay; does anyone know of any vendors or shops in the area where we might be able to find & purchase this type of glass

Thanks in advance!
Amazing Grace I

Look at the PHOTO album section. Jim Lawless did a great fob explaining step by step process for "Replacing Port Windows". He explains the glass was cut and bought at auto glass shop.