Yup, drill all three.
The hatches are still watertight…
…with vented bulkheads. The lack of water in them at the end of the day is all the evidence I need.
How many holes
Per bulkehead?
1 or 2?!?
One hole each bulkhead…
… just above the center, with the smallest drill bit in my arsenal.
(W)hole thing took two minutes 
Glenn
(W)Hole Thing Took Two Minutes!
Cute!