I would suggest something like this.

Your souther ocean is more or les completely cutt off from any tropical waters, so it should have very cold water.
Your "middle" oceans are somehow surrounded by all those islands and are rather undisturbed by cold waters, while only in the northern oceans cold and warm currents are able to roam free and have a little mix-up. That large north eastern peninsula would make a perfect "Europe" that is being warmed by a "Gulf Stream" while the east coast of the western continent is basically Canada.
currents.jpg