The Do's and Don'ts of Crossing a Bar

by Fiona Harper on 12 Nov 2008 Every year, boats are damaged or destroyed, and people have been killed or injured attempting to cross a bar. While bar crossings can be intimidating, careful preparation and sensible seamanship will ensure a safe crossing. The Skipper of the vessel assumes all responsibility for a safe crossing, and ensure that the vessel is appropriately equipped and maintained. Engine failure or malfunction can be disastrous in the middle of a crossing.

Marine Safety Queensland offers the following guidelines for a safe bar crossing, the recommendations being appropriate for many different kinds of craft, but including sailing boats:

If crossing a designated bar in an open boat less than 4.8mt, everybody on board must be wearing a life jacket. Fines apply for non-compliance, but it is recommended that PFDs be worn in open boats of any size when crossing a bar.

If you are crossing a bar for the first time, obtain info from the local marine rescue authority (VMR or Coastguard), marina operators or the local MSQ office. Bar conditions change regularly and it is important to obtain the latest info before attempting your first crossing. Ask about landmarks, the best channel and potential hazards. Consider crossing the bar with an experienced local before you attempt your own crossing.

Check the expected weather conditions, and do not attempt a bar crossing in heavy wind. It is prudent to tell someone of your plans, whether you are out for a day trip, or on an extended coastal passage. Ensure all hatches are locked down, washboards are in place, and loose equipment and ropes on deck are secured.

Allow plenty of time to assess the bar before you cross. Observe the bar's wave pattern, eg the number of waves in a typical set. Give yourself sufficient time to assess where waves break the least. Wearing polarised sunglasses can help you judge the deepest water and the best route, as can watching other boats that make successful crossings.

Inbound Crossing

When coming in, high speed boats (at least capable of 18 knots) should travel at the same speed as the waves. The aim is to travel in on the back of a wave, staying ahead of the waves breaking behind the boat. Watch for wave patterns and deep water before making your attempt.

When approaching from the sea, increase power to maintain speed within the set of the waves
Position the boat on the back of the wave, do not surf down the face of the wave
Adjust the boats speed to match the speed of the waves but do not attempt to overtake the waves
Slower displacement boats should power through at a speed that allows for maintaining maneouvring control. Do not allow the boat to turn sideways to following waves

In extreme conditions, you may need to make the very difficult but vital decision not to come in at all. After a tough passage it is tempting to take risks simply because of the enticement of pending safety once inside a bar. It may well be prudent to stand off in deeper water until conditions improve, or to seek alternative shelter.

Outbound Crossing

The skill of crossing a bar is in knowing the best water by judging the wave pattern, crossing at the calmest point and manoeuvring the boat around breaking waves, and finding the deepest channel.

Watch the sets of swells before choosing the best time to go. Once committed, hold your nerve and keep going. Attempting to turn around in front of an incoming wave can be dangerous. Do not hit the waves at high speed and take them as close to head on as possible. Some bars have breaking waves across the whole entrance and finding a way through may be difficult. Be prepared to take a wave head on and take water over the bow.

..The speed of the boat should match the energy of each incoming wave by maintaining a speed that is sufficient to lift the bow over the wave
..Look for lulls and select a line of least wave activity
..Where possible, cross on an incoming tide when the wave is running with the tide
..Keep your boat generally bow-on as the waves approach and do not allow the boat to turn sideways to a breaking wave
..Head up into the waves and bear away quickly on their backs, creating a zig-zag course
..Accelerate where possible but avoid getting airborne
..Head for saddles which occur between peaking waves about to break
..Navigate quickly clear of the bar once through the danger point
..Take note of leads and marks to locate the entrance for your return trip

Never underestimate a coastal bar. Waves behave differently in a bar situation and even small waves can capsize or swamp and sink a boat. If you are unsure or inexperienced, wait until the conditions improve to provide a safe crossing that you can handle.

You're the skipper. You're responsible.

Comments from Readers welcome!