The answer is environmental stress
If enough ejecta (mainly ash) is sent into the upper atmosphere, the dust particles will block solar energy causing a decrease in temperature. This has happened in the past. Look for the year without summer caused by a volcanic eruption.
Answer:
To swim faster
Reducing the drag. As with all the other tips here this one is not about how strong you are as the right technique smoothes out your swimming using your strength in a much more efficient way.
Work on your kicks.
Secrets of good propulsion.
Balance
Slightly spread your fingers.
Where are you traveling from and to?
