As the cabin in the Trophy 1802 is not a large space, a small heater would be more than ample on the colder or damp days on the water to make things a bit more comfortable.
I purchased this 12 volt ceramic heater from a local automotive shop. Usually, these units are used for additional heat in the back seat of most vehicles during the winter months and simply plug into a 12 volt power outlet. However, as this one has an on/off switch on the unit itself, I wired it directly to the fuse panel in the boat.
I mounted it next to the cabin door, under the wall cabinet.
This particular model is very functional as it swivels and tilts and the internal fan can be set for use with or without the heater mode.
It works really well and does not take long to warm things up. It even adds a bit of heat to the helm area if the cabin door is left open and the side windows and back drop curtain are installed to the bimini top.