Is TotalBoat Halcyon a water-based polyurethane? Eric Boudreau April 26, 2021 19:29 Updated TotalBoat Halcyon varnish is a water-based polyurethane coating which was designed for superior performance, making it suitable for marine applications. Related articles Which varnish should I use? Can I apply TotalBoat Halcyon over an oil-based stain? Will TotalBoat TotalStrip remove TotalBoat Halcyon? Can TotalBoat Halcyon be applied over linseed oil or tung oil? Can TotalBoat Halcyon be applied over TotalBoat Wood Sealer? Comments 0 comments Please sign in to leave a comment.