This video isn't new on Youtube but is is very interesting. It was filmed
off Haleiwa
Oahu in Hawaii waters the past year.
The video shows a spearfisherman having a productive day in the clear waters; at one poin an huge 13' tiger shark appaear lurkinging close by.
Upon spotting the shark, the spearfisherman immediately grabs his speargun and keeps it extended in order to push off the shark if needed. See the video for the images of this thrilling situation.