SELECT SURFER.nickname, Avg(SAIL.Area) AS AvgOfArea, BOARD.Volume, BOARD.Width
FROM BOARD INNER JOIN (SURFER INNER JOIN SAIL ON SURFER.SID = SAIL.[#SID]) ON BOARD.BID = SURFER.[#BID]
WHERE (((SURFER.SID)=[Vpisi ID Surferja]) AND ((SAIL.Area)>14))
GROUP BY SURFER.nickname, BOARD.Volume, BOARD.Width;