The term 'Flybridge' is commonly used to describe the upper deck of a boat or ship, which provides a panoramic view of the surroundings. However, there are several other synonyms that can be used interchangeably. The first one is 'Upper Helm', which is commonly used to describe the area where the captain pilots the vessel. Another synonym is 'Top Deck', which is widely used to refer to the highest level of a ship or boat. 'Sun Deck' is another term that can be used to describe the topmost level of a ship or boat, where passengers can soak up the sun while enjoying the panoramic views. Finally, 'Pilot House' is another term used to describe the upper deck of a boat or ship.