The coal carrier or collier BIRCHGROVE PARK sank during a storm and settled into 160 – 180 feet of water of Sydney’s northern beaches.
After much searching with just an echo sounder, the diving legend Wal Gibbins had located the wreck the previous year and so began one of the most exciting deeper dives available then using single 72 cu ft tanks and ordinary compressed air.
We’d do seven minutes on the bottom and then stage at ten feet until we ran out of air about three to five minutes later.
Sometimes we’d spear a fish – after exploring the wreck and just before heading back to the surface.
The good to eat Boarfish (pictured) was taken using a handspear – a less complicated method which avoided spearlines that could get snagged and lead to other problems.
Deep diving was not without hazards. Once I over-exerted myself while lifting our heavy anchor and chain that had become stuck in wreckage.
While surfacing vertigo set in, then I felt as though my assent rate was being dangerously exceeded – i.e. the feeling I had was that of rocketing fast toward the surface.
In actual fact the assent rate was probably one inch per second, not the six feet per second it felt like!
A rather dangerous error if there was no anchor line to feel and judge the correct speed.
Easy to imagine how other young divers, some with far to many lead weights, failed to surface at all.
On our dive we’d had a 2.5 meter white pointer shark swim-in to check-out the anchored boats just after we’d all left the water.
Bob ‘skippy’ Delander managed to get out fast with his tank still strapped to his back!
From above water it looked like a simple Grey Nurse, but with a face mask inspection a clear ID was made.
Scuba spear fishing was later banned. The logic was more to give reef fish (especially in the 60 to 100 foot zones) a sanctuary away from most free-divers.