Water can condense inside the windway in the head of a tin whistle and start to block the correct flow of air.
Buy a Generation D whistle. Stop worrying and start to learn to play it. Buy a Generation C and B flat whistle for even more fun. Now you can play and have formed an opinion. A tin whistle is a simple instrument, they can be made pretty cheaply and work well.
In my view, videos made of people playing whistles are basically worthless for judging the qualities of a tin whistle.
What do they signify? They are more an indication of the microphone being used, the acoustics of the place where the recording was made, the skill of the player and the loudness and treatment of the recording.
Not treating the recording (eg. compression, equalisation) is a treatment in itself. You are only hearing what a microphone recorded through whatever loudspeakers/headphones/earphones you are using.
See also my comments on “Bad Generation whistles?."
It’s simply to help counteract some of the more hysterical comments you get about Generation whistles and demonstrate their worth as instruments and give anyone starting on the tin whistle confidence in buying a cheap whistle such as Generation.
So, to showcase the Generation whistle here are some videos. I am, of course, not saying that Generations are the only tin whistle worth having, or that all these players only play Generation whistles.
The story seems to have several variants:
Beginner or inexperienced player writes on a discussion board that they didn’t want to buy a Generation because of the dangers of flaws, or had read about bad quality control of Generation whistles so they didn’t buy one.
Beginner or inexperienced player buys a Generation whistle and cannot immediately play all the notes correctly, cannot immediately get all the second octave notes, and/or plays it into tuner and decides that it’s “out of tune” … then they go online, read some other comment about “bad Generations” and declare that theirs is also a “bad Generation”.