Hi jeanne,
I have not done the seagull century yet, but I have heard that it is a very flat ride but with a lot of wind. Last year's had very nice weather but in the past it has been very rainy- tropical storm rainy. I am going to bring rain booties if that is the case. I will also have a thin wool sweater and leg warmers for the morning. I am also going to bring a little bit of food just in case I don't like what is available at the sag stops. I will have 2 water bottles and that should hopefully be enough to get me through to the sag stops. I like to finish a bottle an hour.

good luck!