I want to wear high heels in the evenings and flip-flops in the day. Is this allowed?
As explained in https://www.yachtcharterfleet.com/advice/guests.htm, it is customary whilst on board a luxury yacht to abide by the “bare feet” rule. High heels can permanently scratch and damage the floors and decking areas, whilst black soles can leave unsightly scuff marks which are hard to remove.
Ensure you take appropriate (white soled) deck shoes for walking your superyacht, or go bare foot.
If you wear outdoor shoes ashore, remember to remove them before stepping back onto the yacht.