Theese are NOT viking runes. They are an older Rune alphabet, from around year 500 and earlier. They are called the elder futhark. The viking Rune alphabets have usually only 16 runes and there are several different alphabets from that time.
Viking longship must have had some variety of sails. However, they must have favored the red and white stripes as so much history and art is the red and white sail, usually with a large black bird in the middle towards the top.