The Big Surf Island Add-on for Burnout Paradise has 5 achievements worth 110 gamerscore.
Awarded when you complete all 10 Island Freeburn Challenges. These can be completed by 2 - 8 players
Land the Mega Jump from the Crash TV Ski Jump and get at least 4.5 seconds of Air Time
Collect 15 Island Billboards
Collect 20 Island Smashes
Find all 15 Island events