Bilge Pump Discharge - New Thru Hull ???
You do not stae the size of the vessel but a 3/4 line for a bilge pump is very small. These are normally 1-1/2 in diameter. Once you run this hose to the aft end of your boat, depending on its size, you will have a lot of water in the hose. I would definitely put a check valve in-line so the pump is not cycling all the time. You could easily have a half to full gallon of water in the line depending on the depth of the bilge. Don''t forget you have to run the discharge hose high enough in the boat to prevent back siphoning when heeled over. Yes to Czech valves! Why cut corners by sharing a through hull? It should be a dedicated line, your life could depend on it!