The contraction cracks out on the main body showed up last Wed, it's your first clue to stay off. At the beginning of the season when you first start going out on the new ice at the campground launch, you can plainly see the large gas vent bubbles formed in the ice of the bay. This should be your first clue that this particular ice is going to be much weaker than normal ice. It will also be the first ice to become unsafe in the spring. Throw in the warmer melt water running into the bay, and you have a perfect scenario for a disaster.