2N-COUNT; N-IN-NAMES (五大洋之一的)洋 An ocean is one of the five very large areas of sea on the Earth's surface. (五大洋之一的)洋
They spent many days cruising the northern Pacific Ocean.
他们在北太平洋航行了很多天。
...the Indian Ocean.
印度洋
3N-COUNT 许多;大量 If you say that there is an ocean of something, you are emphasizing that there is a very large amount of it. 许多;大量 [informal, emphasis]
I had cried oceans of tears. [+ of]
我泪流成河。
APEC seems be drowning in an ocean of jargon. [+ of]
亚太经合组织似乎为一大堆空洞的胡言乱语所淹没。
4PHRASE 沧海一粟;九牛一毛 If you say that something is a drop in the ocean, you mean that it is a very small amount which is unimportant compared to the cost of other things or is so small that it has very little effect on something. 沧海一粟;九牛一毛 [emphasis]
His fee is a drop in the ocean compared with the real cost of broadcasting.