Roger,
There a lots of posts in the Archives about this. Typical leaks can come in through the transom if the bolts are loose on the bottom printle. You will find water under the cockpit, but there are weep holes that lead to the cabin. Also the cockpit drain hose can rub and develope a leak. I have had both of these problems on my H23 and they are easy to fix. The leaking cockpit hose could produce a gallon of water after a heavy rain. There are reports that the hose that drains the anchor locker to the starboard drain develops leaks. I have not had this problem yet. My stanchions were leaking this spring. The shelf got wet. I simply re-caulked the screw holes on the offending stanchion. When it rains hard, I can watch drops of water drip down from the side of the sliding hatch. It seems that if the rain is heavy enough, that area does not drain fast enough to keep up. Especiall when I have not cleaned it out recently enough and there are leaves in the slot. Having said all this, except when the cockpit hose had a hole in it, the most water I have ever had to remove is about 1 qt or less. If you have 4-6 gallons, I would start looking under the cockpit for a slow continuous leak through the bolt holes or the cockpit drain hose. Good luck. Keep us posted on what you find.
Bill Leathen - Lake Onalaska