Can Any Laser Beam Reach The Bottom Of The Ocean?

There are countless applications for lasers, including their use in communications and measurements. One of the most fascinating laser-based technologies is LiDAR, or Light Detection and Ranging, which is used for various purposes, including measuring distances to produce detailed 3D representations of an environment. It’s been used to find lost civilizations in jungles, and many have wondered if it could be used to map the ocean floor, as typical lasers can’t reach the bottom of the ocean. 

The ocean is vast, and most of it remains unexplored. As of April 2026, around 28.7% of the ocean floor has been mapped via sonar, but the deeper the seafloor, the harder it is to map. LiDAR could change that by potentially mapping areas where light doesn’t penetrate, which is known as the bathypelagic zone. It begins about 3,280 feet beneath the surface, and while LiDAR hasn’t yet penetrated that far, that could change thanks to the potential of blue diode lasers.

A typical laser, like a laser pointer or even a powerful military laser, cannot penetrate deep into the bathypelagic zone, but that limitation could be overcome with blue laser light, as its particular wavelength can transmit through water with minimal loss. Using a blue diode laser could theoretically penetrate significantly deeper than traditional lasers. While it’s as yet unclear precisely how deep a blue diode laser’s beam might penetrate at high power, it opens the door to expanding beyond the 28.7% of the ocean floor that’s already mapped.

A blue diode laser emits coherent light at a wavelength of around 445 nanometers, offering low energy absorption in marine environments. When IR radiation enters the water, it’s absorbed in around 1 inch, but blue light offers greater potential due to its tight beam. They’re also easier to control than IR lasers, and they have an output power of up to 6 kW, which can be adjusted in milliseconds. Laserline’s new blue diode laser is engineered specifically for underwater use, though it’s not intended for LiDAR.

Instead, the blue diode laser is intended for deep-sea applications where drilling or Remotely Operated Vehicles (ROVs) explore. Instead of using LiDAR from something like a surface boat or an aircraft, a blue diode laser like the one developed by Laserline could theoretically be used on an ROV, which could then use it to map the ocean floor. That’s entirely theoretical at this point, as the primary application of the new technology is meant for algae removal, underwater processing, and other areas where traditional IR lasers are ineffective.

The blue diode laser still cannot penetrate the entire ocean to reach the seafloor thousands of feet below, but if it were installed on an ROV, it could penetrate several feet. That’s exponentially further than an IR laser, which has an effective range measured in centimeters. Ultimately, the answer to the question of whether a laser can reach the ocean floor is no, not from the surface, but there are ways to make it happen, so long as the laser is placed in a deep area near the bottom.