Rio De Janeiro Maru

The Rio De Janeiro Maru was a 137 meter passenger-cargo liner, built in Japan before WWII. She was a work horse of the pre-war world, carrying emigrants from Japan, to South Africa, Brazil and on to the West Coast of America, before returning home, on many voyages. However, during the war, she became a submarine tender, and then a cargo transport vessel. She arrived in Chuuk six days before Operation Hailstone, full of munitions, and desperately needed supplies. She languished in a slow death, after being hit by several 1,000 pound bombs in the first strikes of the day. It apparently wasn’t until about 3 am the following morning that she finally sank to her current resting ground.

Stacks and stacks of beer bottles sitting in hold number 5 of the Rio. Some of them are still in their original wooden boxes!

Bottles in crates on the wall, no wait, spin around, it is actually the floor, or is it the ceiling, it’s easy to get confused in the gloom. Large letters sitting proud in the lopsided bow, spelling the old name, in both Kanji and Roman lettering, amid the sediment and fish. Swim through in to the large cavernous storage decks, taking a peak in to the last moments of the ship, frozen in time. The static prop, once propelling the tons of steel and men through the water to destinations unknown, now sitting, coated in pristine and colorful coral and fish.

The coral growth along the Rio is very beautiful. As she sits reasonably shallow (10-15 meters on the port side of the hull), one can spend a long time admiring the young ecosystem that has formed.
A lantern that has carefully been placed on the deck of the Rio, to try to encourage people not to scavenge. Sadly, for the future divers, it still happens.

Maximum depth to the seafloor is 35 meters, but her port side sits in a nice shallow 10-17 meters. The holds took us to about 28 meters, but there is so much to look at on her hull, one can spend ages ascending slowly.

On the wreck, directions get changed around, up is port, down is starboard, the floor is the wall and the walls are the floors. This is the portside hand rail.. who knows, someone may have farewelled a loved one holding on to this rail over 80 years ago.

Dive Site Review – Blackmans Bay South, Tasmania

Dive site map of Blackmans Bay South

Fifteen minutes south of Hobart CBD (Tasmania) is a fantastic little shore dive, located at the south end of Blackmans Bay beach.  If you love sea horses, stingarees and draughtboard sharks and giant kelp, then this site has to be on your Tasmanian dive bucket list.  Due to its shallow depth it is easy to spend an hour or more exploring this beautiful dive site.

Lots of these seahorses can be found in the shallows of the dive site at Blackmans Bay South.

Entry is off the end of Ocean Esplanade.  There is easy parking with a grass area for you to set up your dive gear.  Once set up, there are two entry options (see the map).  Entry #1 is a short 150 meter walk down on to the beach.  This will give you plenty of time in the water to get set up as
the depth is quite shallow for about 200 meters from this point (~2-3m), but, keep your eyes open, this is where you’re most likely to find the pot-bellied seahorses (Hippocampus bleekeri).  Entry #2 is a longer 350 meter walk along the Boronia Beach Track, and then a short scrabble along the sandstone rocks.  I advise caution when using this entry, as the rocks can sometimes be quite slippery.  However, this is a great entry if you are interested in getting past the eastern point and around in to the giant kelp forest.  The jutting walls on the east point of the dive site are

Biscuit star and jewel anemones that can be found on the walls of the eastern end of Blackmans Bay, Tasmania

encrusted in stunning jewel anemones, and there are always a fair few draughtboard sharks (Cephaloscyllium laticeps) sleeping in cracks or under some weed.

Even in average visibility, this site can be a photographers dream, with plenty of fish and sharks to keep a diver happy for well over an hour!

Parking: 90 degree parking at the end of Ocean Esplanade

Amenities: Public toilet about 700m north of the dive site, on Ocean Esplanade

Depth range: max 10 meters

Visibility: As this site is in the Derwent, it can vary from 2-10 meters