Hi,
I have installed the heater in a space under the propane tank container. You can access this space from the lazarette but the opening is not very large and since I was installing a new Raymarine EV1 autopilot in that area, I decided that is was faster to remove the propane tank container. This is not very difficult, remove 6 screws, unplug the propane drain hose, unplug the solenoid valve wire, unplug the hose to the solenoid valve and remove the hose. You can now lift the container. I installed the heater in this area because it is not used much and I wanted the heater parallel to boat longitudinal axis because I wanted to run the heater even when sailing.
I ran the duct under the shelve in the lazarette, on the high side of the freezer, behind the stove (which I removed to run the duct), in the food locker, behind the navigation center.
I have an outlet in the aft cabin, a large outlet in the chart table seat and one in the front cabin. I will take more pictures and post them. Out 'n About will be hauled out for winter storage on Oct 23 so since I bring almost everything back home I will have more room to take pictures. If you have questions please do not hesitate to let me know. I had a very hard time finding on the net how to install the Websto heating system in a 361. I insulated all the duct with high quality pipe insulation, not the Webasto stuff. I got the insulation from Grainger, 1WZD3 2 5/8 in and 1WZD7 3 5/8 in. I used this type of insulation because the duct runs nesr the freezer and in the food storage area. The duct can get very hot.
I will be at the Annapolis Boat Show so we could meet if you want more details. You can send me an e-mail.