CSY33 - Water Tank(s)?

[CSY33inCT]

I've been unable to locate any schematics or diagrams for the water tank(s) system on my CSY 33 here in Connecticut.  I've heard anecdotally that there may be a tank which extends down into the keel, but so far I haven't been able to locate any actual diagrams (including in the DropBox which - to my eyes - doesn't seem to contain much information on 33's at all). 

I know I've got one fairly large freshwater tank just aft of the mast (with an access plate in the cabin sole between the salon table and the mast) but am unclear on any other tanks - let me know if anyone's got blueprints or a drawing - or even a written description in response to this post would be greatly appreciated! 

Thanks so much!

[Rhapsody]

The CSY 33s had two different tank configurations, possibly because of shallow or deep draft, or for some other reasons.
On my boat the fresh water tank was under the cabin sole and had 3 inspection plates, 1 large plate just aft of the table, and 2 smaller plates forward. The capacity was 153 gallons.
The tank’s inside gelcoat would blister and give the water a foul smell and taste. I ended up sanding the inside of the tank, cleaning with acetone and coated it with West System epoxy as it was “food grade”.
The whole operation took 6 weeks..