The Reggae Marathon has been an organized event since 2001 so this does make it the "18 annual" event. Interestingly enough, the Reggae Marathon web site show a picture bill board and one of the pictures (presumably from last year) is a group standing in about three feet of water. One of the participants is wearing the same shirt.

https://www.reggaemarathon.com/?v=52c5706bc98f

Rob, to many Red Stripes at the Red Dragon and you put on the wrong shirt??