There is a fascinating Mishna (Oral Law given from G-d to Moses) about the seal.
The Torah says that vessels made from the skin of sea animals cannot become ritually impure but vessels made from the skin of land animals can become ritually impure - The exception is the seal. Even though the seal spends most of its life at sea, the Torah defines it as a land animal.
Why? The answer is hinted at in the following story: There was a teenage girl who got separated from her group and was lost on a hike in the woods. She was missing for a few days before someone from the search party spotted her. They called to her, but she didn't respond. Moving closer, they called out again – but there was still no answer. When they reached her, they understood her silence - she was praying the Shemoneh Esrei prayer (during which it is forbidden to speak). What was this teenager thinking? It would be understandable, after being lost in the woods, that she be frightened of not being found. Yet, when her longed-for opportunity for rescue came, she wouldn’t break her silent connection with G-d. There is an amazing connection between this girl’s story and the amazing seal. Rebbe Nachman of Breslev says that there is a “force of return” in the world which draws all created things back to their source in G-d. Returning back to our source in Hashem is just the most natural and comfortable "place" for our souls to be. The essence of who we are is most revealed when we are returning. We can all relate to the distressed feeling of having lost our way. Every creature in the world, when it’s frightened and distressed, wants to return “home.” When toddlers lose sight of their mother’s they run back to their mother’s arms; Salmon fight their way upstream to return back to the place of their birth. So too, when we are consumed by worries and doubts, do our souls yearn to return back "home" to Hashem. The girl in our story had emuna. Her believed that her true “home” was with Hashem. She felt peace, strength and hope through her real spiritual connection. Confusion and anxiety drop off when we stop trying to navigate the challenges, temptations, and difficulties of the world ourselves and return to Hashem instead. The way back to Hashem is a state of mind – an intention. We can even unite ourselves with Hashem in “mundane” daily activities. Getting a haircut, buying new clothes, taking our kids to the doctor are elevated to mitzvahs (holy acts) when our intention is to do these things for Hashem. There are people who stack up hundreds of holy acts every day of their lives because they wash the dishes, do the laundry, clean the house, and read this website out of a wish to serve Hashem. Each activity that we dedicate to Hashem is a lesson in how to connect; to be intimate; to love. We are told that each time we make even the smallest sanctification of Hashem’s name we have added another stone to the building of the final Holy Temple; and, when it will soon be built, we will get the credit for all the stones that we have added. Have you guessed yet: Why the Torah defines the Seal as a land animal when it spends most of its time at sea? The answer is because when the seal is frightened it “returns” back to the land. The Torah defines the seal not by its apparent home in the water, but by where it returns to when under attack. For us too our “home” is not here in this world. We are just visitors here from a far off place. When we feel bombarded by the challenges and difficulties of this world, our souls which were created with Hashem’s Infinite Wisdom, want to return to their true “home.” King David was referring to our souls when he wrote: “You (Hashem) have made them all in wisdom?” (Psalms 104:24) Emuna is the belief that the essence of our selves is a part of Hashem. Our belief that everything comes from Hashem and that everything that He does is for our good motivates us to return to Him in order to live more joyfully and fully in unity with His superior Wisdom. The Torah's rules are the training-wheels that transport us on our return trip. Then, like the girl in our story, physical appetites are reduced and human “rescue” becomes merely an afterthought.