Terminology: Portlight vs Porthole

[SvenG]

Technical terms in a second language can be a real pain !

I've tried to look up the difference between "porthole" and "portlight". I haven't found an authoritative definition or even a consistent accepted use. To find the real truth I'll ask the Internets !

Thanks for any enlightenment,



-Sven

[knottybuoyz]

A portlight is any shape other than a circle.

A port hole is a round so the water can't hit you square in the face!

[Misiu]

I think portlight and porthole are used interchangeably.

[AnchorageGuy]

Porthole
An opening in the topsides or deck structures that allow light in, and which may be opened for fresh air. Portholes are usually small, with a sturdy hinged glass cover called a portlight, that can be dogged shut against a watertight gasket. (From the French "porte" meaning "door.")

Portlight
The heavy glass cover for a porthole that can be opened for air, or dogged shut when the seas are rough.

[osirissail]

If you look at the marine catalogs of yesteryear you will see that "portlights" are fixed glass prisms or transparent material that is permanently mounted mostly in a deck to allow "light" into a dark area of the boat. They do not open. A "port hole" is an "open-able" window in the side of the vessel. In the ancient days they were round but now are mostly rectangular.

[AnchorageGuy]

This is where the definitions I posted came from.
http://tinyurl.com/2u2zuty

[Catamount]

I agree with waterwayguy's definitions. What osirissail is talking about are called "deck prisms"

[David M]

I was taught at the maritime academy that the portlight is the glass that allows light through. It must be able to be opened.

A deadlight is a heavy cover that blocks light from coming through the portlight.

A deadlight can also be a portlight which does not open.

A deadlight can also be a watertight glass or prism in the deck or cabin overhead which does not open.

[osirissail]

Originally Posted by Misiu

I think portlight and porthole are used interchangeably.

Seems Misiu is the winner in this category. See;
whatport

[ViribusUnitis]

I always thought a portlight was a fixture that allows the light in, but does not allow air.

A porthole is an openable hole that can allow air/light and maybe even water into the boat.

[GordMay]

• PORTHOLE is a general term originally used to describe more or less any opening in the hull such as a gun-port.
• DEADLIGHTS are the ‘windows’ which are fixed and non-opening.
• PORTLIGHTS can be opened.
• DECK-LIGHTS are prisms of rectangular or round shaped glass or acrylic set flush into the deck to give a constant stream of light below deck.

Read more: Porthole, Portlight and Deadlight construction and installation.

[Misiu]

Originally Posted by GordMay

• PORTHOLE is a general term originally used to describe more or less any opening in the hull such as a gun-port.
• DEADLIGHTS are the ‘windows’ which are fixed and non-opening.
• PORTLIGHTS can be opened.
• DECK-LIGHTS are prisms of rectangular or round shaped glass or acrylic set flush into the deck to give a constant stream of light below deck.

Read more: Porthole, Portlight and Deadlight construction and installation.

So it is mostly consistent with Waterwayguy's definition.

As always in teminology there are two issues. First - what is the original/proper meaning of the word and second - how most people understand the word. I think it's called generalization.
Also known as extension, generalization is the use of a word in a broader realm of meaning than it originally possessed, often referring to all items in a class, rather than one specific item. Generalization is a natural process, especially in situations of "language on a shoestring", where the speaker has a limited vocabulary at his/her disposal, either because he/she is young and just acquiring language or not fluent in a second language. That's me, and I am not young

[zeehag]

decklights and deck prisms are different from portholes/lights. they are able to be walked on, and are the same thing. the porthole/light is a window in the side of the boat opens for air and light.

[sestina]

Neither! I was brought up to call them "scuttles".

[Astrid]

It is, I believe a matter of differing terminologies in the different English-speaking parts of the world. If I recall, in the RN the term used was sidescuttles, which included the frame, glass and cover. The actual hole was the porthole, the glass, if able to be opened was a portlight, if fixed it was just the glass; The deadlight was the hinged, metal storm cover used in foul weather and when the ship is blacked out.