Citizen’s involvement monitoring large geographical areas over long periods of time is becoming an effective way to support scientific projects. The influx of pelagic Sargassum is a regional problem throughout the NW Tropical Atlantic. While satellite imagery can estimate Sargassum blooms on a regional level, it is difficult to have systematic in situ abundance observations. Additionally, the impacts of Sargassum in the Caribbean vary between geographical locations. Here we present a brief analysis of the citizen science project, “Sargassum Watch”. We piloted the study using two apps, “CitSci” and “Epicollect5.” Three categories of citizens send entries to the project: “target group (n = 36 members)” that have standardized daily or weekly observations associated with established monitoring programs; members of our lab (n = 10) that sends opportunistic observations; and friends, family or the general public (n = 10) that send opportunistic observations. Between March 2018 and October 2019, a total of 1067 observations were reported by participants in South Florida. Most of the observations reported were daily or weekly observations from the target groups (n = 900) compared to our lab members (n = 100) and the public (n = 22). These observations provide a first perspective of Sargassum landings at a large scale. Using the citizen science apps effectively requires in-person training and constant feedback between project managers and participants. We envision strong improvements by adding and maintaining target group engagement supplemented by opportunistic observations from the general public. Regardless of the challenges, this citizen science program has potential to expand Sargassum monitoring efforts at both a local and regional level.