know the lake or body of water and there isn't a safer place to snowmobile.
This year may be an exception to most people's rules though, its been up and down so much that hard clear ice has been scarce in some areas and ice hasn't formed as quick as most years. We usually have 1.5 feet by feb, 20-24" by march. You can drive a dumptruck on it most years in feb (good time to get supplies to island properties). Only around 10-12" right now which is unusual, but more than enough to be safe on stopped sleds. Lake is 10 miles long, 2mi across, over 200 feet deep. Its pretty big and windy and doesn't get ice on the main channel til just b4 xmas time. You can ride it safely by mid jan most years. Last weekend was the first weekend most were running it with 8-10" throughout. was staked by the snowmobile club this week which basically means they take responsability for anyone going through on their stake line.
8-10" will support a multiple group of sleds stopped, no question's asked - its a fact. The only problem is lakes that have hidden springs or creeks don't form ice as solid in those spots.