We have two Vinylmations full of signatures from a
DCL cruise we did in 2012. A word of caution. Keep it in a very very sheltered area. Ours have never ever been in direct sunlight and yet the signatures still are fading rather terribly.

One is a white vinyl and one is a red vinyl. The sigs have faded a lot more on the red than on the white. Sharpies were used to sign.