Just to preface this, if you are in between a juicy bait ball and a starved shark, a well timed punch between the shark’s eyes is the best defense.
Having said that, there are a lot of gimmicks out there claiming to prevent a shark from attacking in the first place. A lot of pricey gimmicks, of course.
There are SharkBanz, shark deterrent wetsuits, and shark repellent stickers to cover the bottom of your surfboard. While I’m not exactly impressed with the small neodymium magnets that so many surfers have been buying for $50+, I’ll actually admit that there may be something to the notion of a shark’s avoidance of poisonous sea snakes. At least enough for the shark to take avoidance measures over prey. Somewhat.
A shark’s vision isn’t the sharpest, so high contrast objects get the most attention- they’re easier to discern. Sea snakes are very poisonous to sharks, and have distinctively high contrast (black and white striped).
Since objects are usually spotted by a shark from below, rather deep in the water column, I figured the best place to put my “sea snake” would be within the back 1/3 area of my surfboard on the bottom. This area is usually somewhat parallel with the ocean floor whether I’m sitting, paddling, or surfing on my board, so it would be the prime location. If a shark looks upward, the “snake” would be visible from below. Or so the theory goes.
I used plain bright white and black duct tape for this project. This combo ensures optimal contrast, especially when waters can become murky at times.
Hey, I don’t warranty ANY of this, yo. If you honestly want to believe any of these gimmicks are going to work 100% of the time, well….bless your heart….