Scupper on:
[Wikipedia]
[Google]
[Amazon]
A scupper is an opening in the side walls of a vessel or an open-air structure, which allows water to drain instead of pooling within the 
There are two main kinds of scuppers:
# Ships have scuppers at deck level, to allow for ocean or rainwater drain-off.
# Buildings with railed rooftops may have scuppers to let rainwater drain instead of pooling within the railing. Scuppers can also be placed in a
Schematics employed in hydraulic diagrams
Watercraft components {{architecture-stub
bulwark
Bulwark primarily refers to:
* Bulwark (nautical), a nautical term for the extension of a ship's side above the level of a weather deck
* Bastion, a structure projecting outward from the curtain wall of a fortification
The Bulwark primarily refe ...
or gunwales of a vessel, or within the curbing or walls of a building.
There are two main kinds of scuppers:
# Ships have scuppers at deck level, to allow for ocean or rainwater drain-off.
# Buildings with railed rooftops may have scuppers to let rainwater drain instead of pooling within the railing. Scuppers can also be placed in a parapet
A parapet is a barrier that is an extension of the wall at the edge of a roof, terrace, balcony, walkway or other structure. The word comes ultimately from the Italian ''parapetto'' (''parare'' 'to cover/defend' and ''petto'' 'chest/breast'). ...
, for the same purpose.
References
External links
Schematics employed in hydraulic diagrams
Watercraft components {{architecture-stub