Here in Houston when North wind blows the water drops at my marina to 1 foot from 5 foot normal, grounding boat. Water level in h260 ballast tank hole is 10 inches lower than normal. I wonder did designers test to see if mud squirts up the partly unsealed bottom round tank hole in this situation? As a positive with less water in tank the strain on dock lines is less. Just wondered. I will swim under later and poke finger in to feel for mud. AND SO FAR THE SWING KEEL SEEMS FINE. Hmmm. D