On a sunless Thursday, News 12 met Zdenek Ulman, who goes by Z, in Haverstraw to board a boat on the Hudson River.

"This river is very alive, like very vital," said Ulman as he steered out to open water.

Ulman admires the beauty of the river and said it's one reason he's chosen the line of work he has.

"We got the first images over here of the sea floor," he said as he pointed to a screen.

Ulman uses a side spin and down spin sonar to identify sunken boats along the rivers floor with his company Marine Diving Service.

In his decade long career, he said he's salvaged nearly 500 vessels across the country.

"Sunken boats today, I believe it's a huge problem," he said. "They are all over the place."

The boats pose many problems.

They leak contaminants, become navigational hazards and break down to produce microplastics and debris.

Ulman said it's a mostly manmade problem, as many of the boats are sunk on purpose.

"They throw the boat out, they take the valuables and they sink it," he said.

Ulman said there is a lack of accountability for boat owners and believes legislative action is needed.

"Those boats should be insured, registered every two years, there should be a check up on the physical state of the boat where it is," he said.