What to Wear
From the Official RTYC Website
Guests are expected to maintain a standard of dress in conformity with the tradition and atmosphere of the Club. ‘Business Casual’ is appropriate throughout the Clubhouse at all times except during weekday evenings after 7pm on the Quarterdeck, in the Cumberland Bar and Coffee Room dining room as specified below.
For the avoidance of doubt, gentlemen are not required to wear a jacket or tie for breakfast nor in the Britannia Bar subject to a collared shirt to be worn at all times by gentlemen. From 1100 on weekdays on the Quarterdeck, in the Cumberland Bar and in the Coffee Room dining room, gentlemen are required to wear a jacket and shirt with collar/roll-neck sweater (ties optional) and ladies should dress appropriately.
Guests should avoid any form of dress that might cause offence. The minimum acceptable weekday dress in the ground floor public rooms and on the Britannia Deck is polo shirt, chinos and sailing shoes or equivalent.
After 1600 on Friday - 1100 on Monday, the weekend dress code is smart casual that may include smart jeans (not frayed, holed or dirty).
Translation
No jeans. No T shirts. No trainers or anything scruffy.