Ok so Im not too pleased with the cabin sink drain dumping into the bilge. I dont need pop, beer, or gatorades going in there.
Anyone pop a hole through the side? Do I need to watch out for any hull liner or other structural shlt?

Is the bottom of the sink at least 6" above the waterline?

On my 242 it drains out the side of the boat I know it's like comparing apples to oranges. I would think it would drain into the holding tank or direct to the out side.

My 292 does the same thing.

On our 05 353 the drain for sink went into the bilge, that's just not cool when a relative pours red Kool Aid into the sink and ends up in your white bilge. I looked into modifying it and was going to install a "shower box" and dump out the stern under the platform like the rest of the factory hook ups. I remember there being some sort of issue with height of the sink relative to the water line also. I called Formula parts dept and talked to them and they said the factory did not want any un-sightly holes in the sides of the boat so that is the reason for all the discharge points under the swim platform, for what its worth.

I think your best option is going to be as Voodoo recommended. Install a shower box with a float switch and tie it in to an existing or drill a new thru hull. At least this one will be above the water line.

This is the main reason why I still have a water tank full of antifreeze from 5 years ago and why I don't invite people out on my boat.

I have read you are not suppose to put holes in sides of the hull on the fastech's. However, I have a 353 with factory air that has a water discharge hole about 12"-18" above the water line on the forward starboard side about two feet forward towards the bow were the u-shape sitting area and the v-berth meet. The funny part is the drain pan for the AC has a normal bilge pump that discharges to a diaphragm pump out the aft or below the swim platform. Just a weird set-up.

The sink draining to bilge upsets me too, I was just going to put it in series with my diaphragm pump with a check valve. Just haven't got to it yet.

I added a through hull fitting for my 353 sink drain. No issues.

I think I'd do the "HEY LISTEN BASTARDS" mod before drilling in to the sides of my boat.

Good to know. Formula for Fun you got a picture of the location you went out the side and what it looks like?