I propose a new layer -- Ocean Surface Currents from High Frequency Radar
This is a near, real-time product much like weather radar so could just be the most recent hourly observations or static 25hr average. It would be a sweet addition to the lineup of great layers.
There are four different grids based on the frequency of radars used and proximity to coast. The 2km and 6km grids have the most coverage but coarsest resolution.
http://cordc.ucsd.edu/projects/mapping/maps/
OpenDAP: http://hfrnet.ucsd.edu/thredds/catalog.html
KML: http://cordc.ucsd.edu/projects/mapping/rtv7day.kml