A porthole, within the context of a yacht, is a circular or sometimes oval-shaped, externally mounted window, which provides natural light, ventilation, and panoramic views to the interior spaces of the yacht. Typically designed to be waterproof and weather-resistant, portholes are often strengthened with reinforced glass and secured with thick metal frames to withstand harsh marine conditions. Additionally, they are usually designed with hinges, or mechanisms for opening, closing, and sealing to prevent unwanted water entry. They not only serve a functional purpose but also enhance the aesthetic appeal of the yacht.

1. One of the finest features of my yacht was an array of well-polished bronze portholes on every side, offering glorious views of the sea. 2. After climbing up the ladder to the upper deck, she located a gleaming porthole and peered out at the blue waters. 3. During the voyage, Derrick would often sit by the porthole, admiring the vast expanse of the ocean and watching the dolphins surf the waves. 4. He gently opened the porthole on the side of the yacht, revealing a breathtaking view of the sunset on the horizon. 5. One of the most aesthetic assaults on a classic yacht is the insertion of modern plastic portholes, which do not match the yacht's grandeur and style.

Fun Fact: The use of portholes, or small circular windows, on yachts or other seafaring vessels can be traced back to the 16th century. Originally, they were designed for practical reasons, such as ventilation and allowing light into the boat's interior. But it was soon discovered that these windows could also prevent water from splashing into the boat, even in harsh sailing conditions. They are specifically designed to be watertight, and their distinct circular shape helps to distribute the structural stress caused by the waves and the ship's movement. Quite interestingly, the use of the word "porthole" originated from the French word "porte," which means "door," and the English word "hole." So, in a way, you could consider your yacht's portholes as tiny, round, and extremely efficient doors that operate to keep your vessel comfortable and watertight!