The Kimberley Coast has the biggest tides in the southern hemisphere. The difference between high and low tides is up around 10 metres in Derby which has the highest tides. Broome, with the 2nd highest, is not far behind.
Whilst the giant tides add to Broome’s unique charm, it’s important to know both the times of the tides, and how high the tides are going to be if you plan to drive on Cable Beach, or want to try your hand at mud crabbing in Roebuck Bay.
We haven’t attempted mud crabbing yet, but we do drive up Cable Beach quite often, as do hundreds of others.
Here’s how the tides occur:
During both the full moon phase, and the new moon phase the Earth, sun and moon are nearly in alignment. This causes the oceans to bulge a little more than usual causing higher than average tides. These are known as ‘Spring Tides’, which has nothing to do with the season of Spring. Rather, the term is derived from the concept of the tide, ‘springing forth’. Spring tides occur twice each lunar month.
Seven days after each Spring Tide the sun and the moon are at right angles to each other. When this happens the bulge of the ocean caused by the sun, partially cancels out the bulge of the ocean caused by the moon. This produces the lowest of the monthly tides, which are known as ‘Neap Tides’.
There’s 24 hours and 50 minutes in a lunar day which is the time it takes the earth to rotate through the tidal bulges. This means there’s 12 hours and 25 minutes between high tides, and the same amount of time between the low tides. So, the tides get slightly later each day.
During the Spring Tide phase, the tides in Broome reach over 9 metres. However, this is not the distance the water stretches up the beach, it’s the actual depth the water reaches. Cable beach has a very gentle slope so each metre of increased tide equates to several metres of increased water up the beach.
There’s a good little beach business here that offers beach chairs and umbrellas for hire. Most of the campers and caravaners here bring their own, but the many tourists who flock to Broome by air don’t have the luxury of being able to bring their own beach furniture. Dozens of umbrellas are set up in readiness at the beginning of the day awaiting the tourists who want to have a day of beach relaxation. Those who are only here for a day or two wouldn’t get to see how well the setting up the umbrellas is timed to coincide with the tides. On an outgoing tide they’re placed virtually at the waters edge. On an incoming tide they’re set up many, many metres away from the shoreline. If we’re setting up our own chairs between the beach flags we place our chairs in line with the hired furniture closest to the water.
During the Neap Tide phase high tide is usually just over 7 metres. During the Spring tides high tide is over 9 metres. This equates to a difference of around 10 metres on the beach. This means that if you plan to drive down Cable beach you need to coincide both your entry to the beach, and your exit from the beach with the correct timing of the tides. During the Neap Tides almost any time is okay. During the Spring Tides you won’t be able to get near the entry to the beach close to high tide in your vehicle, and if you’re already on the beach you’ll have to drive out either a few hours before high tide is reached, or you’ll have to wait a few hours after the tide starts to recede. So, the timing is critical.
We usually time our walks on the beach with the time the tide is going to be quite low. The sand is damp, and hard packed making for a good walking surface. To walk at high tide, particularly during the Spring Tides, would mean walking on softer sand, which is hard work.
Fishing here is best done during the last hour of an incoming time, and for around half an hour of the tide having turned. The Spring tides are rumoured to be the best of the fishing tides. So, if we’re planning to fish from Cable Beach we’ll firstly check both the size and time of the tides, and work out if the tide times will fit in with our daily plans. If they do then we’ll pack our fishing gear, bocce games, bogie boards, beach chairs, drinks and food into the car and head off down the beach at a safe tide time. This usually means parking up with at least an hour two up our sleeves before the tide is right for fishing – so plenty of time for beach fun or relaxation before the fishing begins. So far we’ve yet to catch anything, but we’ve only just really worked out how the tide thingie works. It’s a bit complicated, and has taken a bit of getting our heads around it all. Hopefully, now we have a good grasp of it and we’ll start having some fishing success.
And there you have it – Broome tides explained. Apologies if it all sounds a little convoluted. It really is quite mind boggling when you see the difference between both the high and the low tides, and the difference between the Spring and the Neap tides. It’s only by being here for a while that all becomes clear. It’s only by being here that you can really appreciate how the tides contribute to what Broome is. And in case you don’t know it yet – Broome is amazing!