Here in Juneau the harbor charges $160 for 30 amp and $300 for 50 amp service
. My friend who lives on a 28' Tolly says that 2 1500 watt heaters isn't enough for his boat when it gets cold.
2 gallons a day is a good estimate for diesel fuel
in an oil
stove. Most boats use the Dickinson
stoves which use between 1.3 and 3.2 gallons per day. 2 is a fair average. That comes to $250 a month
When it gets cold there is no way a single
heater is going to keep a boat warm. So I think 2 to 3 hundred per month is about right. The ideal way to go is pay for 20 amp service
at $120 a month and then run the oil heat as needed.