Great story and one to take to heart.
This doesn’t only apply to northern lakes in winter. Northern lakes can also be frigid in spring. So while the air temp could be mild, the water may still be in the 30’s.
As you learned, it’s always wise to wear a life jacket when the water temp is 60 or below.
Dittos about the extra paddle in any kind of boat at any time.
Don’t listen to him. Always wear your life jacket when in a boat.
Even the best of swimmers can be knocked unconscious when falling out of a boat. Even in warm water you can become exhausted and drown if in the water long enough.
A life jacket does you no good if you do not wear it.