Wet.
When it was a 100 hp system a single plate.
Now with the 150 system it's dual plates on a tunnelram.
I don't know anybody that's running a dry system on a boat. It kinda needs to be fuel injected to be running a dry system.
Dry
In a dry nitrous system, extra fuel required is introduced through the fuel injectors, keeping the manifold dry of fuel. This property is what gives the dry system its name. Fuel flow can be increased either by increasing the pressure in the fuel injection system, or by modifying the vehicle's computer to increase the time the fuel injectors remain open during the engine cycle. This is typically done by spraying nitrous past the mass airflow sensor (MAF), which then sends a signal to the vehicle's computer telling it that it sees colder denser air, and that more fuel is needed. This is typically not an exact method of adding fuel. Once additional fuel has been introduced, it can burn with the extra oxygen provided by the nitrous, providing additional power.