I would go inside the cabin with the hatches closed and have someone run a garden hose over the deck. Check one section of the boat at a time and see if you can trace where the water is coming in. Do the feel test.
Then open the lazarette cover and check for water coming in from the cockpit. You boat has a self bailing hose system that is different than what is on my O'Day 222 so you're going to have to trace it out the best way you can.
As Rich pointed out, chainplates, the rub rail, and the self bailing hose or hoses are always suspect. Toe rails are also suspect. It's a matter of visually checking it and feeling for wet spots. Look for water marks on the fiberglas in the vicinity of bolted hardware.
When cleaning your boat, try to stay away from cleansers that contain Oxalic Acid or hull cleaners. This stuff will eat out caulking. You can get away with it on the hull, but don't use it on the deck.
I used this household cleaner years ago that really cleaned the dirt out of Fiberglas Gelcoat. I got the idea of using this stuff out of one of my boat books under "Helpful Hints" After the first rain I had leaks in my cabin up the ying yang. That stuff ate the caulking out of my rub rail. I removed the rail and cleaned and caulked the areal under it and the leaks disappeared. So much for "Helpful Hints"!
On my boat, the rub rail and toe rails have always been the cause of leaks. Sometimes the tabernacle bolts will leak water a tiny drop of water.
These boats shouldn't leak a drop. Stay on untill you find it. It will save in costly Fiberglas repair work down the road.
Joe