A Waterloo Region company’s underwater robots are helping divers off the coast of South Korea search for the still-missing passengers from last month’s deadly ferry sinking.

Almost 220 bodies have been pulled from the wreckage of the Sewol ferry so far. The ferry was on a routine trip to a popular vacation island on April 16, when it took a sharp turn and capsized. 174 people survived the sinking.

Now, searchers must go deeper and deeper into the listing ship to find the remaining missing passengers.

The work is difficult and dangerous, as strong currents and floating debris hamper recovery efforts.

That’s why a remote operated underwater vehicle, created by Deep Trekker of Ayr, Ont., has been deployed to scout out safe passage for the rescue divers. The company has a dealer in South Korea who was able to dispatch the robot quickly. 

“If you can imagine a very small remotely-operated submarine that goes beneath the water and has a camera on it, and you drive that around just like you would a first-person video game,” said company president Sam MacDonald.

The robot is battery-operated, weighs 20 pounds and is roughly the size of a basketball which makes it ideal for this kind of search and recovery, according to MacDonald.

“The portability of our units make it something that is very quick to deploy in situations like this. So where you don’t have a power supply and you can’t use some of the larger, more sophisticated robots. This one you simply put in the rubber zodiac, take it out to the site and throw it in the water,” said MacDonald.

The South Korean ferry sinking is the country’s worst maritime disaster in 40 years. Most of the missing and dead were high school students on a school trip.

All 15 members of the ship’s crew have been taken into custody by police and South Korea’s prime minister has resigned over claims the government didn't do enough to rescue or protect people on board.