I have a GW 335 and have yet to find someone who knows what is circled in red in the attached picture. I have one port and starboard. I am thinking its an LED.. but I didn't purchase that option. One person told me it is part of the helm master system - which I could not confirm.
I've just learned that these are indeed LED lights that are part of the Helm Master system. They are on when you are utilizing 'setpoint' and signal to approaching boats that you might move and to swimmers to be aware that the engines are active.
Hopefully that info gets into common marine navigation literature. Other than a bright light, it really won't mean much to most that don't know about the helm master.