I don't know a lot about the Glind unit, however I note that generally it is fitted without a storage tank. I have always used a traditional heat exchanger with an insulated holding tank, so that hot water (courtesy of the engine's waste heat) is available across the day, not just when the engine is running.
In times not so long ago, refrigeration compressors and the heat exchanger required a half hour's engine running time a day to keep the water hot and the beer cold. It always seemed to work well for me.
The Glind seems to have a lot going for it and, If you do go ahead with it, I would like to hear your impressions. My current boat is equipped with a 12v fridge/freezer (not the equal of the old Tecomseh engine driven compressor and brine tanks) and I am using a solar shower. I intend to fit a heat exchanger and am very interested in the Glind.
I can't agree with the notion of cold showers on a cruising boat. Even in the tropics, after a wet night in the cockpit, there's nothing quite so restoratively comforting as a hot shower.
I have often wondered about using the portable HWS such as this http://www.coleman.com/product/hot-w...0#.U2sLGGeKCN0
Has anyone got experience with these?