It is most important to be suitably dressed for the season and climate. This includes possibly a wetsuit, common enough in our society today, bootees or light runners to protect the feet, windproof outer shell, hat, sunglasses (tied on), sailing gloves, and mandatory, a buoyancy aid. Prepare for all weathers by bringing multiple layers of clothing, including a hat, as conditions can change very quickly.
Killaloe Sailing Club have a limited supply of wetsuits and buoyancy aids for those who are attending a course or just trying sailing. Obviously your own gear will ultimately fit better and be more comfortable and warm.
Killaloe Sailing Club has an online shop selling club-branded merchandise/ clothing at: Killaloe Club Shop. An easy way to look the part!