How to steal a square on a distant continent to work the Great Barrier Reef?

Came across the following situation:

Exploring the world by ship, I found the "Great Barrier Reef", 2 hexes off of a different continent. After some research, it appears the only way to work these tiles is with workers from a city.

Unfortunately, the "Reef" tiles are adjacent to two other civilizations and the "Cape Town" CS. One of the civs is attacking the CS. The Cape Town tiles seem to be the best location for a city, and Cape Town has asked for assistance against the attacking civ.

Are there any good options other than taking Cape Town?

Solution 1:

Why is it so important for you to work the Reef? It will be hard for you to establish a city, then work on your culture in the city. The easiest way is to make a city nearby (if you don't wanna take Cape Town) and buy off the tiles you want.