Well not very much, which adds to your enjoyment of gulet charter. There is no formality on board, unless you want it. Eat in shorts/bikini if you wish. Black tie or fancy dress if you want! For runs ashore jeans/chinos are fine.
When on board you are asked not to wear shoes on all gulet sailing holidays (stones and dirt in soles of your shoes can damage the teak decks on our gulet), so 1 or 2 pairs will see you through. Most people manage with swimming gear plus a small pile of T shirts, shorts and a sweater for cooler evenings on your charter yacht –Turkey generally is not uncomfortable with western dress etiquette except in the more rural & traditional villages, where we advise you to cover yourself reasonably well. At either end of the season you may want to bring a light waterproof top. We now supply swimming towels to reduce your luggage requirements. Suncream and medicinal requirements are essentials. Gulets Turkey.