CoastSnap is a low-cost community beach monitoring system that turns the smartphones that are found in most people’s pockets into coastal monitoring tools. At the heart of CoastSnap is a simple stainless steel smartphone cradle that is installed overlooking a beach in a location that is easily accessible by the public. Using appropriate signage, a passer-by is encouraged to place their smartphone into the cradle, take a photo of the beach and share it to a centralised database via social media (using a hashtag unique to each site) or email. Since the smartphone cradle controls the position and viewing angle of the photo, over time this collection of community images records as a time-lapse video the coastline as it evolves due to the changing conditions.