Bilge & cockpit water when motoring and/or sailing

[Casco bay]

When either motoring or sailing without the engine on my 28 ft 1977 Cape Dory, I notice water being expelled from the bilge (starboard thru-hull). At times, there is also some water in the cockpit that comes up around the base of the tiller. It doesn't seem to matter whether the boat is heeling, in choppy water, or smooth sailing...I've checked below during motoring and noticed no leaking in the engine compartment or stuffing box, nothing coming in around the seacocks...
Any thoughts?

 

[higgs]

Check the rudder tube when underway. My old Irwin had a radiator hose like seal held on with clamps at its post and it was the source of a leak.

 

[Ross]

My boat tends to squat if I am running fast(if you can do that in a sailboat). That seems to put some points below the waterline.

 

[Casco bay]

Leak found

When checking the rudder post, noticed water aft of it and found by feeling around that there was the tip of a screw around which water was oozing. When increasing engine speed, there was increased leakage. I believe the site is from an old fish finder that had been attached at the waterline on the transom. It had apparently been sealed after being removed--- not. Called marine store and was told that I can get an epoxy that will work even when the site is wet. I'm hoping this will hold at least for the season. I'm sure this was the water being pumped out by the bilge pump. I suspect that the cockpit water occurs sometimes as the boat 'squats' (per Ross).
Thanks for the input.