Roona, a small sloop built in 1903, and two 21 foot restricted class racing yachts, Dolphin, built 1933, and Milsonia, built 1929, were added to the Australian Register of Historic Vessels (ARHV).

The register was launched last year by the Australian National Maritime Museum and the Sydney Heritage Fleet to document significant Australian boats and ships built prior to 1965.

Roona has been sailing for over 100 years, but it is not so much age as the chronic shortage of water at the mouth of the Murray that's slowing down the vintage racing yacht.

Ray Hoppen, who bought Roona with his daughter Shelley 10 years ago, races the boat once a month but has run aground in its last two races.

"Other members of … the Goolwa Vintage Boat Club, are reporting the river's got so low their boats are just barely floating at their moorings or there's not even enough water to get to a slipway," Ray said.

Restoring and maintaining the Tasmainian built Roona is a labour of love for Ray, who grew up in a family of wooden boat enthusiasts. Jock Veenstra's Dolphin is a rare 21 foot restricted class yacht built in Queensland.

Jock found the boat in Elvina Bay, NSW and took it to South Australia 25 years ago.

"One of the older blokes here at the time knew Dolphin and the class's history and I became an enthusiast, buying, restoring and passing on another three," he said.

Seven of the original 21 footers can be found in Goolwa, all restored and in good order.

The manager of the register, David Payne, estimates there are only another half a dozen 21 footers left in other parts of Australia.

Jock also brought Milsonia to Goolwa, owned until recently by marina operator Keith Parkes.

Milsonia has had a long and successful life as a racing yacht, winning the interstate race the Forster Cup twice in 1929 and 1932.

Dolphin and Milsonia race regularly in Goolwa as members of the Goolwa Regatta Yacht Club, the oldest registered yacht club in Australia.