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Catch the King Tide 2025: All King Tide Data
Loftis, Jon Derek
Loftis, Jon Derek
Abstract
"Catch the King" is a community science GPS flood extent mapping effort centered in Tidewater Virginia, USA, that seeks to map the King Tide's maximum inundation extent with the goal of validating and improving inundation prediction models like the Virginia Institute of Marine Science’s Tidewatch Map (https://cmap2.vims.edu/SCHISM/TidewatchViewer.html). This 36-hour storm tide inundation forecast model is based on the Center for Coastal Resources Management’s open-source SCHISM hydrodynamic model’s operational outputs, updated every 12 hours at noon and midnight (EST). Timestamped GPS-reported high water marks were collected by volunteers to effectively trace the high water line by pressing the 'Save Data' button in the free Sea Level Rise mobile app (available on iOS and Android) in regular intervals along the water's edge.
Catch the King was founded as a collaborative effort to give members of the public an opportunity to engage personally in climate change adaptation. While the development of the Sea Level Rise app was led by Wetlands Watch and local tech company, Open Health Innovations (formerly Concursive), the idea for creating a statewide program stems from the creative minds of Wetlands Watch’s former Executive Director, Skip Stiles, retired Virginian-Pilot reporter, Dave Mayfield, and Virginia Institute of Marine Science (VIMS) assistant professor, Dr. Derek Loftis. Throughout the year, trained tidal flood mappers use the free Sea Level Rise mobile application (iOS / Android) developed by Wetlands Watch and Open Health Innovations (formerly Concursive) to walk the high water lines in public spaces near them to digitally trace GPS contours of the maximum extent of tidal flood waters. These data are shared publicly after the end of the mapping event and used as a public annual tidal calibration for the forecast predictions generated from VIMS' Tidewatch Map. Annually, a live tidal calibration of the forecasts driven from the Center for Coastal Resources Management's SCHISM hydrodynamic model (developed by Dr. Joseph Zhang) is conducted by the trained participatory scientists engaged with Catch the King, and analyzed by Dr. Loftis at VIMS. Catch the King 2025 took take place on the weekend of October 10-12, 2025, during some of the highest astronomical tides of the year, which were harmonically forecasted to be 3.22-3.63 ft. above MLLW at Sewells Point in Norfolk, VA. The king tide took place at many different times and occurred at different peak amplitudes throughout the Commonwealth of Virginia's coastal region, yet each was forecasted to be the highest tides of the year for those areas.
Catch the King 2025 had 167 volunteers map 27,120 high water marks using Wetlands Watch's Sea Level Rise App during the king tides on October 10-12. The volunteer breakdown for Catch the King in 2025 revealed that the most GPS data points (by region; 6,892 pins) were mapped by 35 community scientists in Virginia Beach. Tied by number of volunteer flood mappers, Norfolk (35 mappers) collected the second-most high water marks, with 5,963, in terms of total mapped GPS flooding extents. VA's Middle Peninsula region collected the third-greatest quantity of data across a very wide area with the help of 29 volunteers mapping 4,433 high water marks throughout the king tide weekend. Here is a daily breakdown of data collected during the 2025 Catch the King Tide Weekend:
36 people mapped early, from October 6-9, documenting 4,765 GPS maximum flood extents and captured 124 time stamped geotagged pictures
61 people on Friday, October 10, mapped 7,395 GPS maximum flood extents and captured 341 time stamped geotagged pictures
77 people on Saturday, October 11, mapped 7,139 GPS maximum flood extents and captured 211 time stamped geotagged pictures
64 people on Sunday, October 12, mapped 7,821 GPS maximum flood extents and captured 200 time stamped geotagged pictures
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Associated Publications
Loftis, J.D. and Katragadda, S. (2025). Best Practices for Flood Model Validation using Community Science. 2025 ESRI User Conference Session 1467, 104653. URL
Loftis, J.D. (2022). Exploring Latent Verification Methods for Inundation Forecasting Models through Remote Sensing Networks and Community Science. Oceans 2022 MTS/IEEE Hampton Roads, IEEE. DOI
Mulholland, M.R., Macías-Tapia, A., and Loftis, J.D. (2022). Water quality impacts from tidal flooding in Southern Chesapeake Bay. Oceans 2022 MTS/IEEE Hampton Roads, IEEE. DOI
Rawat, P., Anuar, K.A., Yusuf, J.E.W., Loftis, J.D., and Blake, R.N. (2021). Communicating and co-producing information with stakeholders Examples of participatory mapping approaches related to sea-level rise risks and impacts. Communicating Climate Change: Making Environmental Messaging Accessible, Routledge, p. 79-96. DOI | Book DOI
Loftis, J.D., Mitchell, M., Schatt, D., Forrest, D.R., Wang, H.V., Mayfield, D., and Stiles, W.A. (2019). Validating an Operational Flood Forecast Model Using Citizen Science in Hampton Roads, VA, USA. Journal of Marine Science and Engineering. 7, 242. DOI
Date
2025-10-22
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Sea Level Rise, Tides, Flooding, Virginia, Citizen Science, Community Science, Inundation Data
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Loftis, Jon Derek, "Catch the King Tide 2025: All King Tide Data" (2025). Data. William & Mary.
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https://doi.org/10.25773/je0a-ag42