我再查了下 IACS UI SC 156 Doors in watertight bulkheads of cargo ships and passenger ships
1. This interpretation pertains to doors located in way of the internal watertight subdivision boundaries and the external watertight boundaries necessary to ensure compliance with the relevant subdivision and damage stability regulations.
这里面又说包括external watertight boundaries ，搞得有点晕
2. Normally closed: Kept closed at sea but may be used if authorized. To be closed again after use.
Permanently closed: The time of opening such doors in port and of closing them before the ship leaves port should be entered in the logbook. Should such doors be accessible during the voyage, they should be fitted with a device to prevent unauthorized opening.
This interpretation does not apply to doors located in external boundaries above equilibrium or intermediate waterplanes.
按照上面说的应该是Permanently closed才需要记录entered in the logbook
3. 根据上面的图片，Power operated, sliding or rolling---- POS， 肯定是这种在海上要使用的形式吗？