Rip current flow behaviour can also be highly variable, again depending on the local geography and the surf conditions. Flow behaviour can include[17]:
- a regular flow dispersing in a ‘rip head’ just beyond the surf zone
- circulating eddies within the surf zone
- short episodic ‘pulses’ forcing water to exit the surf zone following a set of waves
- water and sediment being carried up to 1-2km out to sea during surf conditions with waves higher than about 3m; these are commonly called ‘mega-rip currents’
Multiple types of flow behaviour can occur in any type of rip current. Flow patterns can change rapidly as surf conditions change.
A common feature of many rip currents is that they occur in deeper channels. The deeper water means people can lose their footing and move with the current offshore. Rip currents can flow at up to 3 m per second, which is significantly faster than most people’s swimming ability. This is why trying to swim against a rip current can be potentially very hazardous.
Both circulating and non-circulating rip current systems can be operating on the same beach at any given time, based on a number of factors such as topography, bathymetry and swell conditions.