The fat peace ocean is the Pacific Ocean. The Japanese language thinks this ocean is peaceful, just like English does (the word 太平 actually means "peace").
Note that we're using the alternative meaning of 洋 here! If you didn't learn that with the kanji, just imagine that to get to Western Style places you need to cross the ocean from Japan!
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
on the Pacific Ocean
across the Pacific Ocean
towards the Pacific Ocean
The Tofugu team is planning a company retreat to travel across the Pacific Ocean on a luxury cruise.
That Pacific bluefin tuna in the fridge is Kanae's souvenir.
Nowadays, most pufferfish are harvested in the spring during the spawning season, then farmed in floating cages in the Pacific Ocean.