becki, all water tanks need to be vented, even bladders, 'cuz you couldn't fill or use them without a vent.
1986 boats: as far as I know, the original handful came with V berth tanks, but later 1986 boats removed the V berth thank and put in the starboard settee tank, which is how my boat came. IIRC, #55, Al Watson's old boat now owned by Dave Commando, may have had the V berth tank. The starboard tank is vented to the starboard stanchion just outside the forward end of the galley. Sounds like the one becki's yard bopped for her. I do not know where the V berth tanks were vented.