Safest way to cross a coastal bar

20th April 2021 Jack O'Rourke

Coastal bars are notoriously tricky to navigate, and it typically requires good judgement and the right kind of boat, as well as a little bit of local knowledge to cross.

A bar forms at the entrance to rivers and inshore waterways because of sand drifting along the coasts. Conditions on a bar can change quickly and without warning, even on a good day.

While there are dangerous coastal bars, they often serve as the only way a boat can access, or reach shelter from, open waters, so it is important to know how to cross one. 

Preparing to cross 

Check the tides, coastal weather and warnings before you attempt to cross a bar, and don’t try it if you think it's too risky. You can check the forecasts for hazardous warnings and dangerous conditions on the Deckee app

In NSW there are many web-cams that stream live footage of coastal bars at popular locations along the coast.

The best way to learn about a bar is by asking local boaters, volunteer marine rescue groups or the local marine authorities who cross it regularly. Ask about any leads or beacons that may help you navigate over the bar. Become familiar with a bar by crossing it with an experienced boater before trying to do it by yourself.

It is important to put on lifejacket before crossing a bar. It will be too late if something goes wrong and your boat capsizes, as it is almost impossible to put on a lifejacket in choppy waters.

Make sure the boat is seaworthy, suitable and can handle impacts from waves. Consider your boat’s size, design, structure and buoyancy to determine its suitability for rough waters. Tell someone where you are going, how many people are on board, when you are expected back and who to contact if you are not back.

Making the crossing 

If you haven’t attempted to cross a particular bar before, observe the bar for at least 10 minutes, looking for visible channels indicated by darker coloured water and lack of breaking waves. Take note of the wave period, which is the time between wave crests. Also observe how other vessels handle the bar and the line they follow when crossing.

Find any navigation aids that may help. Aids to navigation are a feature that can be turned on in the Deckee app. 

If possible, time your crossing to coincide with a rising tide when leaving or entering the port, as an incoming tide is always safer.

Going out

When heading out, remember that an outgoing boat must meet the energy of the breaking sea. Idle towards the breaking waves, then apply the throttle and run through once there is a lull in the waves.

If the waves keep rolling in, head for the lowest part of the wave. Motor to the surf zone and gently accelerate, then apply more power and run to the next wave. Back off the power just before contact with the swell. As you come through or over the breaker, accelerate again and repeat the process until well clear of the break zone.

keep your boat head-on to approaching waves, and be prepared to take water over the bow.

Coming in

Coming in over a coastal bar is usually easier. You should try to match your boat speed to be the same speed as the waves. The aim is to travel in on the back of a wave and stay ahead of waves that break behind the boat, so don’t get in the situation where you are running down the face of the wave. 

Maintain power and trim the nose of the boat up a little, adding power as needed. Once you have committed, keep going — trying to turn around in front of an incoming wave should be avoided. 

If you follow this guide, you should be able to cross a coastal bar in a safe way, and once you gain more experience you can pass that knowledge onto other boaters.