Note that the mast on the E-29 is probably deck stepped. Rain leaks might still occur if the mast base has not been re-bedded, tho.Water is coming down the mast. Water after a rain coming down from "inside" the mast is pretty common and ends up in the bilge. Seems your water intrusion is down the outside of the mast from the deck. Check it out. Needs some sealant. Sure wish we knew which Ericson you own...and what year! Might help diagnose the leak.
With boat on the hard, the boat likely has a different tilt than when floating. Many yards like to raise the bow a little bit when blocking it on the hard. If so, the leak could be ANYWHERE forward of where it winds up pooling.THE BOAT IS ON THE HARD.
Good description, prime example that water will find its own way....and the path of gravity is the thing to follow backwards to find the source. My 27 had a leak that was wetting the starboard cushion. Finally found while visiting the boat in the rain. Water dripping out of missing screw hole on trim above seat (where wires run), opened this up to find water running along a suspended section of wire that crossed onto and over the cabin ceiling, with a light and inspection mirror was able to follow moisture to cubby cabinet and mounting of compass on cabin top which was the source. If you'd rather not wait for the next rain, ask somebody to hold a hose, may be helpful...I had to remove the stbd water tank to find that water was running down the sidewall (below the deck fill), then under the stbd setee and water tank and galley cabinets before pooling on the galley sole.