Having already identified all sites bordering the Arctic, Indian and Pacific, it would be allright of course to also have an 'Antarctic Ocean' connection.
But where does it start, and what are its borders? Wiki has an interesting background story to tell, but also mentions that there is more than one point of view of what exactly is part of it. "South of 60° S latitude" is the one Wikipedia uses.

Sites that have been suggested are:
Carlton Exhibition, Tasmania, McDonald, Macquarie, Sub-Antarctic Islands
But neither are south of the 60° .

So I think I would have to reject this connection, or rephrase it into another one that encompasses this group of sites.
Any ideas?

If this connection is to be ommitted all sites should be added to the Pacific but McDonald which can be added to the Atlantic Ocean.

a. I wouldn't regard Melbourne (and Carlton Exhibition) as being on an ocean at all. I remember once reading a blog from some guy who wanted to run a marathon in every continent and was agonizing about which "continent" Hawaii was in - his model of course failed to recognise that not every piece of land had to be part of a continent! Similarly not every island or coastal town has to be in/on an ocean. London isn't on an ocean and nor is Edinburgh - and neither is Melbourne
b. If that part of Tasmanian Wilderness which abuts the sea is on any ocean at all it is the Indian. It is on the west side of the island and Encarta says "Tasmania is bounded on the south and west by the Indian Ocean, on the east by the Tasman Sea of the Pacific Ocean"
c. Mcdonald/Heard Islands are in the Indian ocean (or the Southern if we recognise it)
d. Macquarie Island is certainly Pacific
e. (NZ) Subantarctic islands are certainly Pacific (and, despite their generic name, they are more northerly than Macquarie)

Well - is the Southern Ocean "to be or not to be"? As the Wiki article says the IHO has said it has "been" since 2000 - but IHO's speciality is "ocean currents" and sometimes "a man with a hammer sees only nails"!! If ocean currents are a significant determining factor then why are not the North and South Atlantic and Pacific Oceans regarded as 4 separate bodies? They each have their own "gyre" and the Atlantic has its "shape" and cultural history as being an additional "reason" for subdivision (It mirrors the debate as to whether N +S America are 2 continents or 1. My "eyes" tell me that they are 2 just as my "eyes" tell me that Europe is NOT a geographic "continent" but an appendage onto the single landmass of Eurasia - but let's not travel that road for the moment! It does demonstrate however that cultural factors can be more important than pure geography). But apparently the IHO doesn't regard them as separate. The analogy with the Arctic Ocean isn't relevant as this is clearly an enclosed body of water - unlike the "Southern Ocean". I have travelled by sea from South Georgia (certainly "Southern" and very "(Sub) Antarctic" but just above 60 degrees S. north for 4 days to Gough Island - certainly a completely different climatic zone. Yet both are offically north of the Antarctic convergence. There are NO simple rules which apply across the entire geographic area. And the Atlantic ocean encompasses "Arctic" and "Tropical" climates so there is no reason why an ocean has to consist of a single current system or cannot consist of extremes of climate variation!
On the whole I come down on the side of the traditional definition and do not recognise the "Southern Ocean" for general purposes!! But no doubt the IHO will eventually have its way

I'll drop this connection, as we surely can't find 3 sites that are South of 60° S latitude. The named sites will be distributed among the other oceans (if applicable).