On Summit sunday we had 3 1/2" and guys were going through. When we started the lake was locked up and tight, as it warmed up we started getting water on top. Then around 2:00 PM we noticed the water was disappearing, soaking into the ICE. It got soft fast we wanted to stay for the evening bite but left at 5:00PM. We saw 2 guys go for a swim,that will make you ask yourself "don't ya think ya have enough gills for the year LOL". I just know if we stayed 2 more hours we would have been wet also. Guys this time of year inches of ice don't mean anything 4" can swimming ice. Be CAREFULL and carry you ropes and picks,and most of all don't go alone.