Aside from additional weight, why do ships not have an additional layer of protection (like a double hull) that could possiblly be connected to the main hull via some devices that deploy
![Nigeria to ban single-hull tanker by December — Business — The Guardian Nigeria News – Nigeria and World News Nigeria to ban single-hull tanker by December — Business — The Guardian Nigeria News – Nigeria and World News](https://guardian.ng/wp-content/uploads/2020/08/Tanker-2.jpg)
Nigeria to ban single-hull tanker by December — Business — The Guardian Nigeria News – Nigeria and World News
![Yacht yachting sail boat single hull underway cruise cruising South west Turk turkey Turkish Europe Asia north east Mediterrane Stock Photo - Alamy Yacht yachting sail boat single hull underway cruise cruising South west Turk turkey Turkish Europe Asia north east Mediterrane Stock Photo - Alamy](https://c8.alamy.com/comp/AT88NA/yacht-yachting-sail-boat-single-hull-underway-cruise-cruising-south-AT88NA.jpg)
Yacht yachting sail boat single hull underway cruise cruising South west Turk turkey Turkish Europe Asia north east Mediterrane Stock Photo - Alamy
![Typical Single and Double Hull Configurations (Original source taken... | Download Scientific Diagram Typical Single and Double Hull Configurations (Original source taken... | Download Scientific Diagram](https://www.researchgate.net/profile/Yan-Syaifudin/publication/322896255/figure/fig42/AS:631630301524034@1527603807548/Typical-Single-and-Double-Hull-Configurations-Original-source-taken-from-William-Rcac.png)