Both of SeaBee's two Otter Unmanned Surface Vehicles were present for the fieldwork at Runde. One of the Otters is hosted at NTNU in Trondheim, whereas the other sits with NIVA at their Grimstad office.
The Otter that resides with NIVA, nicknamed "RobOtto", is equipped with three different sensors.
On the front, it has a downward-looking single beam echosounder, also known as a habitat mapping echosounder. It's made to measure the depth and also to classify the seafloor type. This sensor can distinguish between harder and softer seabed types, as well as the thickness and density of aquatic plants like seagrass and kelp.
The second sensor measures the water's salinity and temperature along the surface.
Finally, the third sensor is a C3 Submersible Fluorometer with three optical sensors. The first of the optical sensors measures the presence of chlorophyll A, which tells us about the presence of algae in the water. Then there's a turbidity sensor, which measures the amount of particles floating around. The final optical sensor measures what is known as "CDOM" - Color Dissolved Organic Matter. This usually comes in from land sources, such as rivers and streams into the sea.
The Otters are configured so that they follow a route quite accurately, usually in a "lawn-mower" pattern and along the shoreline. The Otters can adapt to the local geography and topography, avoiding obstacles and reaching speeds of up to 6 knots.