I put the bilge hole too low like an idiot. all sealed and glued down extremely tight. how could i plug it in a simple yet effective way. i would use a regular rubber plug but the bilge hole's brass fitting has a little ridge that makes the plugs not fit.

Marine grade sealant Nut, bolt, and two washer.

Nut and washer on one side, bolt and washer through bilge hole filled with the sealant.  Tighten snug.   after sealant dries reply some to the nut and the bolt from both sides of the repair.

Should hold for quiet some time.

Marine grade sealant Nut, bolt, and two washer.

Nut and washer on one side, bolt and washer through bilge hole filled with the sealant. Tighten snug. after sealant dries reply some to the nut and the bolt from both sides of the repair.

Should hold for quiet some time.

Here's a modification to the above solution.

Make sure you have excess marine sealant to get a good bead on each side. Slide the washers up to the sealant to spread it, but do not squeeze it out.

Once the sealant cures/sets (depending on the type) you can tighten the bolt and nut. It will compress the sealant which cannot be squeezed out, making a watertight seal on both sides.