The best sprays on the market are ONLY good to 20 feet MAXIMUM so you better have big cahoona's to stand and wait for them to get close.
Any wind at all and you can cut that distance in half.
Best bear "spray" is a shotgun with buckshot.
Oh, sorry. Where are you going? Baxter??
One thing I will tell you is to get a green stick about 3 to 4 feet long and at least one full inch in diameter. Use it as a walking stick and IF you see a bear (I have seen three in the wild while hiking the last 30 years) make yourself as big and noisey as you can.
NEVER RUN AWAY, always move while FACING the bear. Use the stick if the bear persists but I don't think you have anything to worry about in Maine!