My 1987 223LS has been getting water under the step as you walk into the cabin, noticed it cause carpet was wet and when I stuck my hand under the step theres a small bilge area that fills up everytime I go out, and then I have to shop vac it dry.
I'll eliminate a few things fir you
1 no water has come over or onto bow
2 hatches are closed
3 rear bilge is dry
4 boat was dry after it was washed and re-checked before it went out.
This is driving me nuts as I like to keep a spotless boat, any ideas where the heck water is coming from? I'm thinking of removeing the fuel tank access door in the cockpit floor to see if anything is going on in there but it looks like a royal pita.

The seal under the windshield frame is leaking. The seal dries out and lets the water in.

Do a search this has been covered before. Lots of info on the problem.

Check out this thread.
http://www.offshoreonly.com/forums/s...ght=water+step

I am dealing with the same problem. Keep in mind I get water under my step every time I use the boat. We have not had rain for months, and I don't use water to wash my boat all the time. When I do the step is dry afterwards. As soon as I go to the lake water starts coming from somewhere.

I used to have that problem when I had in and out used to leave boat in water Sat night. Now that its on a lift I am not getting water anymore

I dont get it, step dry, take the boat out no hot rodding, easy cruise 1 mile up river no wakes nothing to splash up under rail, nothing on deck or windshield I mean very easy run and when I get there I check area under step and the SOB is full!
This is going to be a tuff one to figure out. At least if I slammed through some heavy wakes or had some splash I could see this. Also boat is never in the weather its always inside so I dont get it.

I found on my 311 that the thru-hull fitting for sink drain was cracked and allowing water in under right conditions

Does your speedometer work?
Is there a drain opening that connects that area to the rear bilge? If so, try putting a plug in there (after you dry it all out). Also, you might try flushing some water through to confirm it drains into the rear bilge. Maybe put a plug in the engine room end also.
God save me for this idea...but have you gotten underneath and checked the keel & hull for signs of a crack?