海 joins water 氵 with 每 (every, also the sound): where every water ends up. All rivers run to it — the character says so: the every-water.
海 is vastness itself: 上海 (Shanghai — 'upon the sea'), 海外 (overseas — where 华侨 communities live), 人海 (a sea of people — every Chinese holiday photo), 海归 ('sea turtles' — the pun for returnees from studying abroad). 海内存知己，天涯若比邻: 'with a true friend within the four seas, the world's edge feels next door' — distance, dissolved by 海.
Every 每 water 氵 flows home — the SEA.
海归 (returnee from abroad) puns perfectly with 海龟 (sea turtle) — China's overseas graduates are affectionately 'turtles' swimming home.