380 S2: 380 S2 Holding tank vent location and other questions

[jbinbi]

Getting the boat ready for the season here, and realized as I was working on the head, I don't know where the holding tank vents are. Are the under aft end of the bridgedeck?

Also, my starboard locker in front of the mast has a drain from the hatch cover inside lip, but no hose to the bottom of the locker, my port locker has a hose going from the inside lip(don't know what this is called, it is the seating area of where the hatch edge goes) to a drain. see pic. But does this locker actually drain if it fills with water?

The stb locker has the drain on the lip, but no hose, and no exit with a thru hull like the port locker has. But I know water drains out.

[rabbi]

On our 4 cabin layout the vent is at the hull side, 20cm above the waterline next to the holding tank.

our front lockers are just the same. Both lockers drain through simple holes in the bridge deck (hidden under clamshell covers).