Guys. I love the advice. Most of it. But some of you...let's not over do it. This isn't a fricking submarine. This isn't a thru-hull. I already have two holes, GASP...filled with instruments, both 400$, that don't work. The company is defunct. I bought the boat that way.
The theoretical is well and good. The panic is not. I spent 5 years sailing the south pacific. We weathered two typhoons, and about a trillion squals. A cockpit speaker placed vertically, three feet up....with a hole of about 4 inches...with a speaker in the space, taking up entirely the same space as the instrument before it....
A wave 5 feet tall, rolling into the cockpit...I'd say, you're in the wrong boat, to start with. You better be playing some good tunes, because you're dead, anyway.
Second, even if it did occur, the cockpit would fill...and if you speaker were on the floor, perhaps it would pop out. Most probably, the force would be dissapated, and it would not. Not a big deal. The speaker isn't on the deck. It's above the cockpit. You guys act like 1) waves routinely roll over boats, not spray, but giant waves, and then sit, like some Matrix effect, hanging in the air while the boat fills with water.
You're overdoing it. Gallons per minute would only be a factor if one turtled. I know a boat that turtled, with the hatch open. The guy was on deck. He never mentioned what happened to his speakers. He lived.
The holes are there. I'm cautious. This is a fricking 30 foot Cat, not an offshore boat. Enough with the Sky Could Possibly Fall,
Remember: spreading panic artificially is the President's job.
But thank you, anyway.