DemographicsSurprise Bay is approximately 37.39 square kilometres. In 2016 the population of Surprise Bay was 0. The population is 0% male and 0% female. On average the monthly mortgage repayments in Surprise Bay are $0 to $299. The most common weekly income bracket is $0 to $149 per week. Weekly rents in the area are on average $0 to $74.