Plans for building a LARGE tank

[Chuck & Jennifer Brinegar]

Hello...   Occasionally someone mentions something to you that you just have to find the answer to. This happened last week.   Well..Where could I find the plans for a 300 - 500 gallon + tank.  The guy I'm asking for (John) said "I'd like to use marine plywood and Plexiglas for its construction". I know that they exist...just can't remember where.  He keeps mentioning things like " I like it so-big that I could jump-in". He's been around with SW fish for about 15 years...   I'm kinda curious also...   Thank you for reading this and any help you may have   Chuck