Boating Tip: MetEye forecast maps keep you safe

People in small craft (from kayaks up to runabouts) often consider 15 knots as a key wind threshold when deciding whether it’s safe to head out on the water.

The notion that conditions don’t become difficult until the wind reaches 15 knots may work as a basic rule of thumb, but it does not allow for any of the huge number of other variables that contribute to seafaring safety.

First, the prevailing wind needs to blow across a large stretch of water to build up the rough seas that can become dangerous to small boats. If you are near the coast, with the wind blowing from the land, water conditions may be calm even in 15 knot winds; but the further away from shore you travel, the rougher the waves will become. Then, when you start to head home into the wind, the waves will also be right on the nose.

Furthermore, different designs and sizes of boats respond very differently to varying wave conditions and heights.

Wind waves of half a metre are known to swamp smaller vessels, and because of this, State Marine Safety Agencies recommend skippers slow their speed to minimise crew discomfort.

In September this year, MetEye, the interactive map-based weather viewer on the Bureau’s website, was upgraded to provide a far more comprehensive wave forecasting service for Australia’s coastal waters.

As shown in the accompanying graphic of Port Phillip Bay, the wind wave height map can clearly indicate which areas of water are sheltered by land masses that reduce the wave height.

This is useful for kayak and canoe users, who can use the maps to identify days or areas where the wind wave height will generally average less than 0.5 metres. Fishing charter operators, meanwhile, can use the wind wave and swell maps to help clients pick the best ‘weather windows’ in which to head out on the water.

Recreational boaters are encouraged to use these improved MetEye functions as part of their 'five vital weather checks' before heading out on the water.

As conditions can change rapidly, skippers are also advised to continue monitoring the weather via www.bom.gov.au and VHF weather broadcasts at regular intervals during their trip.

More information go to: www.bom.gov.au/australia/meteye

Marine and ocean services: www.bom.gov.au/marine