What are the difference between a Watertight door and Weathertight door?

Watertight Door-that doors which are designed to prevent water from outside. These door are designed to maintain the ship stability which should be involved in a unfortunate accident.

In order to make sure these rules are followed and still remain practical, ships make use of watertight doors below the waterline. These doors are usually constructed by a specialize enclosure maker, then fitted into the ship. These doors "break" the continuity of a structural bulkhead therefore they reduce the strength of that bulkhead. Because of that, they must be engineered to match the bulkhead's strength and therefore watertight doors can look quite bulky and menacing.

There are many types of the door such as Marine quick Action Anti-pressure watertight steel door as I showed before https://zjspeedhorse.blogspot.jp/2016/12/marine-quick-action-watertight-steel.html

Weathertight is lower watertightness compare with the Watertight Door,  Weathertight door is designed to be located on the deck of ship/boat above the waterline, where they can be subject to the adverse weather conditions experience offshore.Weathertight doors are also designed to withstand brief submersion experienced from green seas.

Advantages of the Watertight Door:

-Flood-Protection Barrier

-Normal-Use Commercial or Residential Door

-Allows Easy Access to the Building or Home

-Can be fitted with standard panic hardware

-Standard or custom sizes available

-Easy installation and retrofit