The estimated height of these turbines would be twice as high as the Sydney Harbour Bridge.

These structures off the Newcastle coast would be like having massive North Sea oil rigs there.

Large offshore wind turbines proposed for the Hunter and Illawarra regions could well be visible from the shore on clear days.

Nautical maps indicate that the ocean floor 10 nautical miles off the Newcastle coast is more than 300 metres deep and comprised mainly of sand and mud, with some rock. This ocean depth would necessitate building these wind turbines as floating structures.

There would be issues servicing these structures, and major additional investment in transmission infrastructure where it comes ashore.

It is not realistic to consider just one element of these types of systems in isolation when looking at project costs and benefits.

When the Kurnell desalination plant was built in southern Sydney, all the existing water supply mains ran "downhill" to the coast.

The remedial work to modify the water supply system to take water produced by the plant cost as much as the plant itself.

Newcastle is the busiest coal export port in the world and has a constant stream of bulk carriers entering and leaving the port.

These vessels are hundreds of metres long and weigh many hundreds of thousands of tonnes. They carry away massive cargoes of coal loaded in the port.

Often bulk carriers anchor up offshore around Newcastle while waiting to be loaded in the port to avoid paying demurrage charges.

By contrast, Bass Strait is much shallower than the ocean off Newcastle at about between 60 metres and 100 metres close to shore.

There are a number of oil rigs in Bass Strait near Lakes Entrance that are permanently secured to the bottom.

IN THE NEWS:

Lakes Entrance is the only substantial port at the eastern end of Bass Strait and is the base for the largest commercial fishing fleet in Victoria.

Local and visiting recreational vessels on the Gippsland Lakes also use Lakes Entrance. It is operated by the Port of Gippsland Lakes.

The entrance is dredged to maintain its existing navigability. Maximum depths are up to 5.5 metres in the Entrance Channel between the training walls and 6.5 metres for the ocean bar.

Large ocean vessels cannot enter the Port of Gippsland Lakes.

Apart from ocean liners and bulk carriers travelling along the NSW coast, there are also thousands of smaller vessels travelling north and south along the coast each year.

As well as vessels being relocated from one part of the coast to another, numerous yacht races are conducted along the NSW coast throughout the year.

Any wind farm towers located off the coast would have to be extremely well lit at night in order to warn boats.

Just imagine if one of these floating towers became loose and was drifting around in the navigation lanes.

More than 20 years ago we brought a mate's boat down from Southport to Bobbin Head in Sydney and got caught in a strong east coast low off the NSW coast.

It was like being in a washing machine for two days and the weather system was hundreds of nautical miles wide.

We could hardly see a thing in the day time and absolutely nothing at night.

If we had hit something like one of these towers on that trip we would have disappeared without a trace.

It's a mighty big ocean out there, and you feel awfully small in any vessel in those big storms.

Large offshore wind towers could also have major impacts on property values along the NSW coast where many high-rise apartments are being built close to beaches and shorelines.

Potential purchasers of apartments with high elevations would not want to look out at dozens of wind towers off the coast, especially in the more scenic areas of the coast where housing prices are at a premium.

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