Whoa! - careful there Sailor.

I never said drain to the bilge, YOU did.
No, I'd rather glass-in an under-berth "rode compartment" with a sealed access hatch for maintenance & cleaning. I'd be thinking about half the size of a laundry basket. The chain pipe (3" PVC?) would be sealed at deck & berth, with an access hatch cut from the berth, separate from the pipe - largely depends on what you see under that deck & under that berth. You'd need an optional pipe cover on deck (fitted canvas?) to help safe-guard this pipe from filling the compartment in heavy waters. But, design the compartment to a limit of no more than 3 or 4 gallons.
You might also want a scuppered thru-hull, above the waterline, yet below the berth - or just design-in a bilge pump - or just use a manual bilge pump when required. Plan to minimize the amount of water and mud that goes in (or might get in) there. You'll be displacing some flotation, but you might easily substitute an air mattress on the v-berth.
The alternative - an anchor locker - seems even more complex to me. You'd need to cut thru the foredeck, suspend a sealed chamber from the underdeck, create a hatch cover, and maybe still drill a thru-hull for draining it.
But - guess there's lots of ways to skin this cat. You still might be WAY ahead by stowing your rode at the cockpit~!!! I ALREADY HAVE an anchor roller AND anchor locker, and I'm thinking the rode might be best kept aft. 