Small islands rely on limited freshwater resources and lie at the forefront of climate change given the impacts of rising sea levels and more frequent and intense coastal storms. Sable Island is a small, low-lying sand island in the Northwest Atlantic that has been designated a Canadian National Park Reserve to preserve its unique ecosystem of wild horses, grey seals, and endangered sea birds. Approximately 20 freshwater ponds exist across the island in locations where the water table intersects the land surface in local depressions. Historical aerial imagery reveals a pronounced loss of surface freshwater (pond shrinking), indicating a concurrent decline in the water table elevation. Also, some ponds exhibit tidal signals, revealing a hydraulic connection between the ocean, aquifer, and fresh surface water. To monitor ocean-aquifer-pond interactions, we installed stilling wells, piezometers, and temperature rods in 5 ponds and used the near-infrared bands of Planet scene images to quantify pond area and beach flooding. For each pond, a volume-area-depth relationship was created to establish a connection between satellite-based analysis (pond areas) and in-situ pond level monitoring. Estimates of pond areas from the level data and volume-area-depth relationships were compared to areas extracted from satellite images, yielding comparable results. We used meteorologic and coastal hydrodynamic data to determine the drivers that control pond levels. Results show that pond levels respond to both variable climate conditions and coastal beach flooding, and demonstrate the utility of satellite imagery for long-term hydrologic monitoring in remote island environments.