WebMatrix Database.Open… Close() and Dispose()

ASP.NET Web Pages framework examples of the Database helper do not include calls to Close or Dispose because the framework itself is designed to call Dispose for you at the end of a request. If you use ADO.NET instead of the Database helper, you should employ using statements. Having said that, there is nothing to stop you from wrapping Database helper calls in using blocks:

IEnumerable<dynamic> floaters = null;
using(var db = Database.Open("MyDb")){
    var sql = "SELECT * From LifeRafts";
    floaters = db.Query(sql);
}

If you wanted to manage it all yourself, you can simply call Close or Dispose. They both result in the connection being returned to the ADO.NET connection pool anyway.