Interior leak on 1969 Columbia MK11

Looking for any suggestions on locating leak inside the cabin. I am new to this, so explain slowly. We went out sailing noticed floor filling up with water. I am not sure where to start… It is only inside the cabin under the wood it is not coming from the bolts. However, I do see gurgling from the bathroom direction.

This isn’t something that can necessarily be answered here. Too many variables. I’m more of a small boat one-design sailor so cruising boats are not my thing. That said, your head probably has a Y valve that can direct waste to either a holding tank or directly out through a through-hull into the open water. This valve should always be switched to directing waste into the holding tank (unless you are offshore) and the through-hull closed. Could that valve be open allowing seawater to back in?

I am sorry for posting this… I need help with information from experienced sails men… I am a newbie, however, I am hooked. Even when I seen the floor fill up with water. I still wanted to sail. I didn’t want to go in. You see I am in San Diego, so once I got out of the harbor into open ocean. I have never had so much fun. Furthermore, sinking could become a big problem. So I came to the experts. I will check this valve because the other compartments were clean and the bubbling seems to be coming from the corner facing the toilet area. I will check into where it is located and how to check… If you have any advise throw it my way.Thank you Michelle