My husband and I are puzzled by a phantom leak that appears on the cabin sole of our 37.5 intermittently. It is located in the middle of the sole just aft of the bulkhead between the forward cabin and the main cabin. It consists of about one half cup of water. It seems not to be related to how much rain we get. It sometimes appears when there has been no rain. We have checked overhead and there is no water at all . Where is this coming from? We are stumped. Any ideas? Alice C.