Hiya
Marwaan, firstly, i'm probably even more scared of large sharks that what you are!!
Shark encounters vary in how urgently you need to get out of the water. Things such as size and specie of shark and viz. play an important role. Sharks that are considered man-eaters, the Great White Shark, Tiger, Mako and Bull Sharks are the most notorious. If you encounter one of these, especially a large shark (2.5m+), your best bet is to get out IMMEDIATELY.
With smaller sharks, many spearo's continue to spear fish with the sharks in attendance. Even though sharks are small, they're still capable of causing you to lose a limb, so rather get out of the water if you feel that the sharks are getting agitated/excited.
In the clean deep water, we sometimes encounter small Mako's (2-2.5m). Since the water is extremely clean, i have no problem spearing tuna when there are mako's around. How-ever, should the water be dirty, i'd leave the area immediately.
My GREATEST fear is to encounter a GWS in dirty water!! Fortunately, i've only encountered them in very clean water, possibly becuase i now very rarely dive in dirty water. One incident i wish to recall: we were diving on a wreck in 8-10m water when i saw a 2.5-3m shark cruising about 2m off the bottom. I dove down, trying to see if there were any fish following what i thought to be a Zambezi shark. Minutes earlier one of my mates had seen a large Zambezi and just warned us not to let our fish struggle too much, because once the Zambezi starts taking fish from your spear, its pretty much impossible to continue spearing as the shark would go into a feeding frezy and simply take every fish you manage to shoot.
As i dove down, i angled towards the shark, gliding quite close, but not looking directly at the shark. I was more interested in what fish was following or underneath the shark. When i got below the shark, i looked up and saw the white belly and immediately recognized it: GREAT WHITE!! Slowly swam back to the surface, where both the guys in the water see's the shark. The one guy decides to jab the shark in an attempt to scare it off, but when he see's its a GWS and not a Zambezi, he decides not too!! On goes the powerheads and the boat is called.
How-ever, this shark had other idea's. The water was very clean, 15-20m viz. and we were in 8-10m water. He kept dis-appearing from view, only to appear behind you!! That was the first time i witnessed a GWS trying to sneak up to a diver. Once you spotted him, he'd simply turn and dis-appear, only to re-appear seconds later from behind you. Really scary stuff!! Can't even begin to imagine how that would've ended had the water been dirty!!
Another incident was when a 4m+ GWS surfaced in the middle of 4 spearo's in the water. Agian, we had exceptionally clean viz., 15-20m, and the shark approached us with-out any of the four divers seeing him!! Unbelievable well camoflauged.
Bottom line: sharks are part of spearing. Respect them. Don't dive in sharky area's in dirty water or with fish on a body stringer. When a shark appears, remain calm and stand your ground. If you must leave the water, do so slowly and with calm movements. Always keep your gun pointed to the shark and always keep your eyes on the shark. Remember, a average spearo with a 1m gun and long bladed fins in over 4m long in the water, so you'll look quite big to a shark.
Hope that helps!!!
Regards
miles