Water leaking into cabin '92 230 Sundancer

[Drewbie_G]

I have a 1992 230 Sundancer that's in great shape overall, have owned it for 5 years. Initially there was a small amount of water that would accumulate on the carpet between the head & fridge area, but it would dry quickly. Then noticed water would accumulate in the underseat storage bins (on both sides) in the forward cabin. This season has worsened further, now the carpeted seam along the bench seating in the forward cabin is wet all the way from the bow to the aft bunk area. Not only that, but water is pooling underneath the cushions/mattress in that aft bunk too. Have to pull all the bench seats / cushions out, soak up the water, and run fans overnight to dry it, after each day on the lake. This only happens if the boat is run on plane, not if we cruise at trolling speed (nor, if it's just docked in its slip). Also, heavy rain accumulating water up on deck doesn't produce this effect either. I'm thinking maybe water is splashing up through the clamshell vent on the bow near the anchor box, or another vent on the hull? Hoping it's not a hull-to-deck joint problem. Welcome any advice on this.