Crossing a bar safely by Kaspar Lenigas

Coastal bars are extremely scary to a lot boaties and they have every right to be worried about crossing them, particularly in big seas. But with a good understanding and knowledge of how a bar works, bar crossings can be very safe and easy.
WHAT IS A COASTAL BAR
A coastal bar is where the sheltered waters of rivers or bays meet the swells of the ocean. Bars are inherently dangerous and at times, very unpredictable. Even on a good day, conditions on a bar can change quickly and without warning. There are many coastal bars located around the Australian coastline, and they are a fact of life for most offshore anglers who intend to fish for large ocean going pelagic and reef fish.
HOW A COASTAL BAR WORKS
There are many different bars located around the Australian coast line, none are exactly alike they anglers often have their own different ways of crossing them, but there are a few key things that bars have in common.
Most bars will have some form of channel, where the water is at its deepest. Channels are the safest and only way to cross a bar, but can be hard to spot and it is always best observing at a distance before crossing a bar to see where the waves do and do not break to locate a channel. Some boaties watch where other more experienced boat drivers cross and follow them.
There are also shallow banks on most bars, these areas are where the waves break, but sometimes these banks aren't often clear depending on the stage of the tide and the amount of water on the bar. Usually, with a decent set of swell they will reveal themselves, and it is best to avoid these shallow banks as it where most boaties become unstuck.
It's also worth remembering that coastal bars are ever-changing places; they hardly ever stay the same for very long. There is a lot of sand movement under the surface of the water where you can't see, and a channel that was there one week will be gone the next, so every time before you cross the bar, make sure you have a good look and assess what's happening.
Bars will usually have swell on them, and the height of the swell, direction, periods between swells as well as the tide will drastically affect how bad the bar will be. Both incoming and outgoing tides can cause pressure waves on a bar as there's large volumes of water coming in and out of the bar. Usually, the safest time to cross a bar is around the top and bottom of the tide, where tidal flow is at its slowest. As most know, the moon drives the tides, so around the full and new moons the tides are bigger with a lot more current flow, which can make bars extremely dangerous. So be careful crossing a bar when there are bigger tides.
PRESSURE WAVES
Pressure waves are extremely dangerous and make a bar very unpredictable, these mainly occurs on outgoing tides around full and new moons, or after heavy rain and flooding. Swell size and direction isn't the only thing that governs the wave height on a bar, the swells can almost double in size and become very unpredictable when they meet the pressure created from the large volumes of water pushed out by an outgoing tide.
More often than not it's best to avoid crossing a bar on an outgoing tide and waiting until either the top or bottom of the tide to cross. Usually the top of the tide is the safest time to cross. The incoming tide on some bars can also create deadly pressure waves as it can push swell up and over shallow banks, or the fast tidal flow can become undertoed going over a drop off, creating pressure waves which push back into a bar and into the oncoming swell.
You can still cross a bar if there are pressure waves, but be extremely cautious when coming or going out and always travel at a safe speed.
WHAT TO DO BEFORE CROSSING A COASTAL BAR
Before even crossing a bar it's crucial to have the right kind of boat that is sea worthy enough. Usually anything over 4m can do it safely on a good day. I personally use a 4.8m SmartWave centre console. Even though it's a smaller boat, it can handle a bar extremely well as its very sea worthy, incredibly manoeuvrable and is virtually unsinkable.
There has been many times where I have been able to cross a bar in my boat but much larger boats are unable to, this mainly comes down to knowledge, experience and knowing how to handle your boat. It is also crucial to make sure your boat has a good bilge pump, in case you cop a wave over the bow and need to remove the water fast.
I highly recommend taking a good bucket as a last resort to bail out water. In my opinion, most boats should have a good bucket on board, as they are an extremely useful bit of kit to have.
On the day or days prior to planning a trip offshore make sure, check the conditions, as you can usually tell how bad a bar will be by checking tides, swell size and direction and winds. All the info you need to check the conditions is available on numerous websites such as Bureau of Meteorology, Coast Watch, Seabreeze and Willy Weather.
The general rule of thumb I find is when swell is under 1.5m and coming in on a slight angle to a bar with an incoming tide, and winds are under 15 knots, a bar is generally pretty safe to cross and go offshore.
If the swell is coming straight in on a bar, it can make it very dangerous as there's no shelter or refraction to minimize the swell, so the swell will come head on into a bar.
If can time your trip with a high tide when you leave and come in, it makes crossing very safe. It is possible to cross a bar in worse conditions, but it will take more experience and knowledge over time before attempting.

HOW TO CROSS A COASTAL BAR

When crossing a bar you must keep a level-headed approach. Never freak-out or rush your approach. As per the law, always wear a life jacket when crossing a bar in any boat at any time. A boat can capsize quickly and it is almost impossible to put on a life jacket when the water is choppy.
When I approach a bar, I will make sure any loose items in the boat are secure or stowed away. Then I will assess the condition and look for a deep channel to cross. If I can't really see what's going on, I will approach with great care to take a better look. Remember, waves will generally break in one spot and lose most of their energy, so keep a safe distance between you and where waves are breaking when getting a closer look.
Once I have found a safe channel, where waves aren't breaking, I will radio the VMR and advise them of my intentions to cross. I will then approach the channel at a safe and reasonable speed. When going through a channel, you may come up against breaking and cresting waves, and if you're not comfortable, you should abort. If you do, do so decisively and between sets, so you don't get caught side on.
If you can't abort and turn away, its best to take a slow front on approach when hitting a breaking or cresting wave - getting airborne can get you into a lot of trouble. Most of the time when crossing a channel though, you'll come up against unbroken swell.
I find it best to angle your approach when going over unbroken swell, as you get a smoother ride and won't become airborne or loose speed.
Once through the bar, radio back to VMR letting them know you have crossed safely. With a GPS, it is wise to mark your track, so you have a safe route to follow when you head back in, and also make a land mark of where you came out of the bar. Coming back in through the bar is much safer than going out in my opinion.
Once you've had your day's fishing and decide to head in, make sure you radio into VMR again letting them know your intention to cross. Before committing to head in, it is best to wait for a decent set of swell so you can ride in on the back of the biggest wave, this is so that there's as much water as possible under the boat so you don't run aground.
When heading back in through the bar, make sure you follow your track and look for the clear channel. When sitting behind a wave, it's a good idea to have your engine trimmed down a little more than usual, and never run over a breaking wave, as it can be disastrous.
When the wave you have followed has broken never go over it too fast. The aerated water from the wave can cause the engine to cavitate and stall. If you can hear the motor slightly cavitate, trim the engine down and reduce the speed a little. Once you are in the safety of sheltered waters, radio back into VMR letting them know you are safe.
STAY SAFE
I hope you find all this information very useful and it gives you that bit of confidence to cross a costal bar. Always remember to keep a level head, stay cautious and aware at all times and if you're not sure or aren't confident, don't do it. Wait for another day or get an experience boatie to show you. It's never worth risking your life and the lives of others.
Stay safe and good luck out on the water.