You can walk around the Mediterranean sea by following the countries that boarder it as well as the coastlines.
However walking around the Mediterranean sea would be a long and difficult journey and require you to traverse multiple countries as well as involve traveling by boat between some of the Islands.
There is no single path that is continuous around the entire Mediterranean Sea.
The water temperature of the Mediterranean Sea is often in the 50s and 70s throughout the year.
Although the temperatures of the Mediterranean Sea can vary greatly depending on the location and season.
In spring the water may still be a bit chilly for swimming but summertime the water would be warmer.
In the Mediterranean Sea there are not any significant Tides and sharks are also no issue.
However it's not recommended to swim in the Mediterranean Sea as it is a small and enclosed sea with violent storms, the waves do not have the room to spread and during a storm the waves have a shorter length (distance between two peaks).
The slope is way sharper as well.
If you do go swimming in the Mediterranean Sea you should always have someone with you.
The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land.
The Mediterranean Sea also provides a natural maritime route, facilitating trade and communication between Europe, Asia, and Africa.
The Mediterranean Seas relatively calm waters and numerous ports allow for easier navigation compared to other bodies of water.