Refers to a facility for small boats and yachts, similar to a marina or a berthing area. The term is a compound of 海 (sea) and 駅 (station), evoking a 'station on the sea'.
Many yachts are moored at this marina.
Compound of 海 (umi, 'sea') and 駅 (eki, 'station'), literally 'sea station'. The exact origin is uncertain; it may be a coined term for facilities serving as bases for marine leisure.