With the existing jetty proclaimed unstable, the Department for Transport Energy and Infrastructure (DTEI) said the closure is necessary to ensure public safety during construction.

Rated as one of the country's top fishing and diving spots, access to most of the existing jetty was closed in December 2004 after it fell into disrepair following major storms

Plans to build a new $3.9 million structure were announced in September 2006, after the local community rallied for the future of the old jetty.

Key stakeholders, already reeling from a drop in tourism since the jetty was first closed, said the closure would be a small price to pay to get a better facility.

Local interest groups and the state's peak fishing and scuba diving associations accept the need for the closure, as long as the new jetty is completed as expected.

The DTEI anticipates the jetty will be completed by the end of the year, weather permitting.

"It (the closure) is unfortunate … but the end defines the means; it's something that has to happen to get what we want," Glenice Galbraith, a spokesperson for the Friends of the Rapid Bay Jetty, said.

"If it means the jetty will be here by Christmas - do it.

"It's been almost four years … some people believed it would never happen."

Ms Galbraith, along with representatives of the Scuba Divers Federation of South Australia (SDFSA) and the South Australian Recreational Fishing Council (SARFC) agreed that the occupational health and safety issues involved in the construction made the closure necessary.

The executive officer of the SARFC, Trevor Watts, said that although stakeholders were told access to the jetty would be maintained at a meeting with government project managers on May 15, the contracted construction firm, Bardavcol, has since stated otherwise.

"Bardavcol said the equipment (to be used during construction) makes for an occupational health and safety issue … so that shuts down any counter-argument we could make," Mr Watts said.

"It's something we couldn't fight; it might drag the construction process out longer."

Mr Watts said the construction of a new jetty alongside the existing structure could potentially benefit anglers, providing two marine habitats instead of one.

Antony King, a representative of the SDFSA and a member of the Friends of Rapid Bay Jetty, said that while the closure would prevent diving from the shore, access would still be available by boat.

He said interstate or overseas divers who travel to the area would most likely be affected by the closure, but SDFSA plans to post the information on its website.

"The new jetty will be much easier and safer anyway; that's the price local divers are prepared to pay," Mr King said.

"Once they lay the pylons on the site, we'll be breaking out the champagne."

While shore divers currently face a long swim to the dive site, the new jetty would see a much shorter 30 metre swim for diving access.

If construction was to be delayed, however, Mr King said he would consider asking the government to reopen access to the old jetty over the Christmas holidays.

Steel pylons have been ordered from Encounter Bay-based company Steelpipes, with work on the coating of the pylons prior to construction to commence in August.