src: upload.wikimedia.org
Semi-submersible may refer to a self-propelled vessel, such as:
- Heavy-lift ship, which partially submerge to allow their cargo (another ship) to float into place for transport.
- Narco-submarine, some of which remained partially on the surface.
- Semi-submarine, which cannot fully submerge.
- Semi-submersible naval vessel, which partially submerges to minimize being observed.
Or it may refer to a semi-submersible platform, which is typically transported to a location where it is placed in service.
Source of article : Wikipedia