Sadly, it has happened again, a snowmobiler into the lake through thin ice. Every year, at least one person goes through the ice on a snowmobile. This time it was a 16 year old youth with his life and potential fully ahead of him.
Lake ice should be at least 5 inches thick for snowmobile riding,, an inch thicker than for safe ice fishing. The weather locally has been so mild this season that the ice fishing derbies have been canceled.
One website sagely states that a snowmobiler shouldn’t trust other riders’ judgment regarding the safety of the ice; you should check it out yourself. This teen does not appear to have been doing anything really foolish (that can’t be said for all snowmobile into the lake deaths, like “jumping” open water). It was a terrible, unfortunate accident.
You lose consciousness in 40 degree water in approximately 1 hour, much quicker in colder water (lake water around here is 35 or less). Unfortunately, confusion precedes unconsciousness in hypothermia. Struggling actually accelerates body heat loss in cold water, so attempts at saving yourself must be methodical, yet rapidly effective.
It appears this young man did all he could to save himself, but rescue came too late.
Snowmobilers should carry with them, tethered to themselves and easy to get to: a cell phone in a water-tight bag or case, ice picks (with retractable covers) or a knife to help pull themselves out of the water over the ice, a flashlight with a beacon flasher and “alarm”. Movements to get out must be conservative with minimal body movement (foot/leg “flipper” action), stretching out over the ice or breaking repeatedly through the thin ice toward shore.
Unfortunately, as the body rapidly loses body heat, time is severely limited. Drowning can ensue in the most conditioned of individuals. Nature, as in many cases, can certainly be exceedingly cruel in these situations.
(as you suggested cheryl1054)