Just to be clear, this race was around "Grey Rocks Island" as described by the map detailing the race course. The actual "Grey Rocks" formation is described as a "rocky shoal" http://www.deepcovekayak.com/map/grey-rocks/ . A shoal is further defined as "a place where a sea, river, or other body of water is shallow" or "a sandbank or sand bar in the bed of a body of water, especially one that is exposed above the surface of the water at low tide" http://dictionary.reference.com/browse/shoal . Therefore, a shoal is navigable.
Other than that, pretty fast TT by me. Much better than my last race 2 weeks ago when I couldn't get my boat adjusted right. Hip positioning felt excellent and the boat was moving well except for the portions closer to shore when the reflected waves made staying stable and having good boat roll difficult. I tried not to wash ride the tugboat sized waves from Shane and Dion at the finish but what can you do when a freight train rolls by.