Water-borne vessels are constructed of various materials, ie steel, aluminium, wood, glass reinforced plastics (GRP). Steel is used for large vessels. Aluminium is used for very small craft and for on-board structures, ie minor bulkheads, deck houses, guardrail and awning stanchions, non-watertight doors and furniture. Wood is used for pleasure craft, yachts, small to medium…
Dry dock (graving dock). This is an excavation faced with solid masonry which is connected with a harbour, river or basin. The entrance is closed with a sliding caisson, a floating caisson or dock gates. Water is admitted through special valves until the level of the water in the dock is the same as that…
Miscellaneous ship terms. The following are nautical terms used for various ship’s fittings and structures: Deck head. This is a ceiling in a ship. Bulkhead. This is a wall in a ship. Hatch. This is an opening in a deck to allow vertical access between decks. These can be small hatches for the passage of…
The Hull. This is the main part of the ship. It is divided into three sections, namely the fore part, the midships part and the after part. The fore part ends in the stem, which is the leading edge of the hull. The after part ends in the stern, which is the rear end of…
Although there are many natural hazards that confront man on land, being a land-based creature, his natural instincts allow him to cope with them most of the time. At sea the situation is different. It is not man’s natural habitat or environment and he has to learn new skills in order to survive and operate…
Nautical Almanac. The data recorded in the nautical almanac is usually recorded against UT (universal time or GMT). This is for convenience sake and when looking up any of the information one has to convert the zone time to GMT. In the case of the predicted times of sunrise, sunset, morning and evening twilight as…
Zone designations. A ship’s clocks will not necessarily be altered the moment she enters a new zone. The fact that she is crossing a dividing meridian and entering a new zone does not alter the time she is keeping. Her clocks are altered to suit the convenience of those onboard. Local mean time. Local mean…
Standard time on land. The boundaries of time zones on land generally agree with that at sea, which are defined by the meridians 7½°, 22½°, etc, except when modified as necessary by the territorial limits of the countries concerned. Zone time on land is referred to as standard time. For example, the landmass of South…
A uniform time keeping system has been adopted for use at sea to ensure that all vessels within certain defined limits of longitude keep the same time. The world has been divided longitudinally into 24 zones of 15° each with the system centred on the meridian of Greenwich. The centre division lies between the meridians…
Introduction. Because of the international nature of sea travel where vessels traverse large distances, especially in east/west directions, time is a very important aspect of the mariner’s life. For convenience sake a “24 hour clock” is used. This means that by merely looking at the time will indicate whether forenoon or afternoon is referred to,…
