I read a small boy’s novel in 1950’s about a boy travelling to see his father on a Cessna? (or other small plane) which crashes in a Canadian lake. He befriends an otter (from memory) which catches fish for him, has some adventures and eventually escapes the situation. I have forgotten most of the details but think that he dove down into plane to recover things and had a run-in with a bear. Best thing I can recall is the front cover drawing of the young boy sitting on the lakeside with the otter beside him.
It is definitely not “Hatchet” by Paulsen which appears to be a very similar plot published much later in 1987. I have not read this book but assume it is not a reprint of the original book I am recalling.
I think this is High Country Adventure by Marian Rumsey. The cover is not the same, but a drawing inside the cover is a boy, his dog, and some small forest animals sitting by a lake.
I believe the book you’re looking for is titled “ strange companion“ by Dayton O. Hyde. It’s about a boy who runs away from home and ends up in a small plane crash somewhere in Canada. The pilot doesn’t survive the crash, but the boy befriends a crane that catches fish for him, etc.
He ends up having to survive the winter in an old cabin and blazing a trail through the Canadian wilderness.
I also read the story as a child, and it’s one of my favorites. From how you describe it it sounds like it might be one in the same.
And if neither of those are it, here are two lists on Goodreads that might help:
https://www.goodreads.com/list/show/85995.Middle_Grade_YA_Wilderness_Survival_Stories
https://www.goodreads.com/list/show/17332.Best_Wilderness_Survival_Books