Cambridge
School of Navigation John Starkie, PhD, RNR
U Uniform
You are standing into danger
Una rig
A rig popular in the British yacht racing scene in the 19th Century, The vessel was broad in the beam and transom. It had one mast, stepped far forward between the bows and a single fore-and-aft sail, usually gaff-rigged.
On a broad reach and when running downwind the CE moved far forward of the CLR, giving the boat significant weather helm. Downwind in strong winds they became unmanageable.
Una boats were similar to catboats, which are still popular in the USA.
Under way
The IRPCS, Part A, Rule 3, "General Definitions", says
“ (i) The word “underway” means that a vessel is not at anchor, or made fast to the shore, or aground.”
“fast” means ‘fastened’ or secured: unrelated to speed!
Beware of interpretations or summaries of the IRPCS: changing the words always changes the meaning. Wikipedia states that a vessel adrift is not under way: this conflicts with the IRPCS definition, which must take priority.
Under weigh
The anchor has broken from the seabed but has not yet been catted.
See weigh.
Union Jack
A jack is a flag flown from the jackstaff at the stem of a ship. Ships of the (British) Royal Navy fly the Union Jack: the same flag flown on British soil is known as the Union Flag.
The Union Flag surrounded by a white border and flown from a jackstaff was a Pilot Jack before 1970: it showed (or summoned) the presence of a pilot on board a civilian or merchant ship. It is now sometimes used (perhaps illegally) as a civil (rather than military) Jack.
Ships of the US Navy also fly a Union Jack, but not the same one!
Universal time
Universal time (UT) is a time standard based on the Earth's rotation: it replaced Greenwich Mean Time (GMT) (which was the mean solar time at the Prime (Greenwich) Meridian) in 1935.
Coordinated Universal Time (UTC) is a time standard based on International Atomic Time, which is controlled by the vibrations of Caesium atoms in an atomic clock. It is the same, within about a second, as UT and is adjusted, when necessary, by adding leap seconds to a year.
Standard time separates the world into twenty-four time zones, each zone covering 15° of longitude and each different from its neighbours by one hour. The Greenwich (or Prime) Meridian runs down the middle of time zone UT (time zone 0, or 0000) through London, Western France Eastern Spain and Algeria, although France, Spain and Algeria have chosen to be in time zone -0100!
In terrestrial terms, the next time zone to the East of time zone UT is time zone (UT+1): most countries of continental Western Europe are in time zone (UT+1), often called Central European Time (CET).
The next time zone to the West of UT is time zone (UT-1); the Azores Islands and the Cape Verde Islands are in time zone (UT-1). Iceland has chosen to be in time zone UT.
In nautical terms, the next time zone to the East of time zone UT is time zone -0100.
The next time zone to the West of UT is time zone +0100.
The Earth rotates toward the East, so that the sun rises in the East. When the sun is overhead Austria (15°E longitude) it is noon (1200CET) in Central Europe. An hour later (at 1300CET) the sun is overhead Greenwich and it is 1200UT (or GMT) in the British Isles.
In 1895 George Hudson introduced the ludicrous concept of Daylight Savings Time (DST) or Summer Time, according to which clocks would be advanced by one hour during the Summer months. It made the evenings longer and the mornings shorter! British Summer Time (BST) is the British version of DST. BST is UT+1. 1230UT is therefore 1330DST (or 1330BST).
Most of continental Europe has DST in the Summer; 1230CET (1130UT) is 1330CET+1 (1230BST) in the Summer. Some countries of Continental Europe have double Summer time (double DST) which adds 2 hours to CET.
Up and down
The anchor rode is vertical but the anchor is not yet free of the seabed.
'apeek', from the French a pic.
Uphroe
An alternative (accepted in 1815) spelling for 'euphroe'.