canIswim

What wetsuit do you need in Port Macquarie?

If you buy one suit for swimming in Port Macquarie, buy a nothing — it covers 7 of the months people actually swim here. The sea runs from 20.5°C in August to 26.4°C in February.

Swimming and surfing are not the same answer

Nearly every wetsuit chart online is a surfing chart, because surf brands publish them — and surfing is close to the worst case. A session runs one to three hours, most of it sitting still on the board with your torso and head out of the water and in the wind. Little heat is being made and plenty is being lost.

Swimming is the opposite. A steady front crawl produces several hundred watts continuously, and you are horizontal and fully immersed rather than sitting in a breeze. Open-water swimmers routinely go a full step thinner than a surf chart says. Applying one number to both is where the usual charts go wrong, so both are given below.

Month by month

Month Sea Swimming Surfing Also
January 25.7°C nothing boardshorts
February 26.4°C nothing boardshorts
March 26.1°C nothing boardshorts
April 24.8°C nothing boardshorts
May 23.1°C nothing boardshorts, or a rash vest against the board
June 21.9°C nothing, or a rash vest boardshorts, or a rash vest against the board
July 20.7°C nothing, or a rash vest shorty or a 2 mm top
August 20.5°C nothing, or a rash vest shorty or a 2 mm top
September 20.6°C nothing, or a rash vest shorty or a 2 mm top
October 21.8°C nothing, or a rash vest boardshorts, or a rash vest against the board
November 22.3°C nothing boardshorts, or a rash vest against the board
December 23.9°C nothing boardshorts, or a rash vest against the board

What thickness does not fix

A thicker suit buys time, not immunity, and it does nothing about the two things that actually catch people out: the cold shock in the first minute, and how cold you get after you are out. Neoprene that is soaked and in the wind cools you faster than standing there in dry clothes would. Get changed straight away rather than standing about in it.

Fit matters more than millimetres. A wetsuit works by holding a thin layer of water still against your skin; a loose one keeps flushing that layer and replacing it with cold sea, and a baggy 5/4 will lose to a well-fitted 3/2.

Other coastal cities in Australia

Where these numbers come from

Sea temperatures are the NOAA OISST satellite climatology for the water off Port Macquarie; the thicknesses are retail and open-water convention rather than physics. Individual cold tolerance varies far more than the bands do — people differ by a couple of degrees in both directions, and acclimatisation over a season moves it further. Treat this as a starting point, not a prescription. Full method.