The Port Phillip Heads is closing to commercial ships as hundreds of swimmers make the treacherous heads crossing from Point Nepean to Point Lonsdale.
The annual Rip Swim has 103 registrants taking part, they’ll be taken out to the start by the Searoad ferry around 8:00am.
Under the watchful eye of standby boats and kayaks the swimmers are due in water around 9:00am where they’ll embark on their 3.5km swim across the entrance to the Port Phillip Bay.
Event organisers have secured a pause to large ships using the busy gateway in and out of Melbourne from the Port authority.
The swim is considered one the most difficult in the country due to the large currents swirling around the heads, a second crossing is due in Winter.
Douglas Mew is credited with first swimming between the heads in 1971.