Why is lenina so disturbed by the sight of the ocean-brave new world?

Lenina is disturbed by the sight of the ocean-brave new wold because, In Brave new world, on their first date (lenina and Bernard), Lenina realized that Bernard doesn't want to be around people. She finds it awful when he refused to take soma and his insistence to the ocean. She just fell comfortable and think all is well when they go to bed together.