What are the differences in ocean water temperatures?

The temperature of the water in the ocean depends on latitude: it is different at different latitudes. The water is warmer closer to the equator. Within one latitude, the ocean is warmer off the coast of the mainland.
Also, the temperature is different at different depths: the deeper, the colder the water, since it is not fully warmed up by the sun.
The temperature is influenced by geographic location, the presence of volcanoes, warm and cold ocean currents.
An interesting fact: the warmest waters are in the Persian Gulf, the coldest ones are in the polar latitudes.