Swimmers, surfers and boaties may notice the ocean rising a little higher at the moment. However, there’s no cause for alarm - it’s just the conjunction of a new moon and a supermoon affecting the tides.

The moon takes roughly 28 days to orbit the Earth, while the Earth spins on its axis, taking 24 hours to completely revolve.

Localised inundations can occur during high tides and supermoons. Photo / Michael Craig

A new moon occurs when the moon is on the same side of Earth as the sun and is invisible to the naked eye, except for in a solar eclipse.

It’s widely known the moon’s pull has an effect on the world’s oceans, causing tidal movement. When it’s aligned with the sun, that pull is increased.

Now throw in the fact the moon is also at its closest point to Earth this year, making it a supermoon during the perigee (the closest point during the elliptical orbit over the lunar month), and the effect is even stronger.

This natural phenomenon can lead to some coastal inundation and localised flooding. Global heating, which is predicted to raise sea levels by up to 30cm by 2050, according to the UN, will intensify the effect, and monthly flooding is almost certain to occur in low-lying coastal areas.

Global heating will exacerbate the effects of high tides in the near-future. Photo / Michael Craig

For now, though, anyone in or near the water at high tide should be aware of any potential localised inundations, an increase in the number and strength of rips and unusual currents around estuaries.

And keep looking skyward for the sliver of a young moon in the western sky after sunset.