I can give real world figures from 1982-1986 and from 1993 thru 1996. In a motor sailor (boat capable of 8 knots both under power and sail--and a range of several thousand miles) the first cruise was 41,000 miles, and the engine had 4000 hour on it. This would be about 2/3 of the time the engine was running--much of the time a a fast idle. Fuel costs were vastly lower--the most we paid was a dollar a gallon, but we carried 700 gallons, and purchased some fuel at 14 cents a gallon--which was enough for a years cruising! We figured a thousand dollars a month--and this was fairly accurate. There were a few unexpected--like back surgery and my insurance had not been paid by the shore side folks! We truely belive that a least one trip a year should be scheduled for return to your "home" city. repairs, even in a new boat can be much more than expected. Today I would figure that the same life style would be closer to $3000 a month. This would be eating out several times a week, and a few drinks at bars; the occasional car rental (although we carried motor bikes also) There were also excursions inland by air or common carrier. For example--chart guides and books can be a significant expense--and many times the good guides for Europe are not available in the US--or may be in a language other than English. Even paper charts are expensive--we traded, but at one time had 2000 chartsa aboard. Bob Austin