http://www.wakemakers.com/resources/...-vented-loops/

I have vented loops on all fill lines. No passive filling or draining but they are bulky, spenive, and a PITA to mount in the rear lockers up high under the gunnel.

Criss Cross your vents/drains to the opposite side to negate the dribble effect.

Less holes is more. I'd combine vent/drain lines to a single thru hull all day long before drilling another hole.