02 Feb 2011 10:09 GMT
Nabs and the crew of Britannia III were watched off the line on Monday 31st January by the official Woodvale support boat and many friends and well-wishers in Puerto de Mogan. They finally left the dock at 12:04 GMT. After the first 24 hours at sea Britannia III and her crew are making steady progress towards the finish. Top speed during the day was around 4.3 knots.
The knot is a unit of speed equal to one nautical mile per hour, which is equal to exactly 1.852 km/h and approximately 1.151 mph. The knot is used in meteorology, and in maritime and air navigation—for example, a vessel travelling at 1 knot along a meridian travels one minute of geographic latitude in one hour. The term comes from counting the number of knots which came off the reel of a chip log in a specific time.
Britannia III is capable of doing around 4 knots solely with oars, and depending on the sea, can go over 10 knots. Britannia III will also be rowing 2,602 nautical miles from the Canaries to the Caribbean.
The nautical mile (symbol M, NM, Nm or nmi) is a unit of length corresponding approximately to one minute of arc of latitude along any meridian. By international agreement it is exactly 1,852 metres (approximately 6,076 feet). It is used especially by navigators in the shipping and aviation industries, and also in polar exploration.
The nautical mile remains in use by navigators worldwide because of its convenience when working with charts. Most nautical charts are constructed on the Mercator projection whose scale varies by approximately a factor of six from the equator to 80° north or south. It is, therefore, impossible to show a single linear scale for use on charts on scales smaller than about 1/80,000. Since a nautical mile is, for practical navigation, the same as a minute of latitude, it is easy to measure a distance on a chart with dividers, using the latitude scale on the side of the chart directly to the east or west of the distance being measured.
The Ocean Rowing Society (the official adjudicator of Ocean Rowing Records for Guinness World Records) has now set up a comparitive chart showing the positions of Britannia III, Hallin Marine and Sara G (Britannia IIIs competition) against the current world record holders La Mondiale. It is interesting to watch the progress on this site to see how Nabs and his team are comparing to the current world record holders.
In the first 24 hours Britannia III covered 74.67 nautical miles and had a VMG of 2.71 knots.
To explain the figures on our progress page…the VMG is “velocity made good” and refers to the velocity (speed) made good towards the finish line. The DMG is “distance made good” which is the distance travelled by the boat towards the finish line based on the shortest route (i.e. as the crow flies). A crew will always row a greater distance than the DMG, simply because they will not be able to row a shorter distance than that of the ‘crow’.
The DTF is the distance to the finish and quite simply is the distance between a crews last known position and the finish line. It is important to bear in mind that Britannia III is travelling south-west at this stage, so do not read too much into the speeds (VMG) and distances (DMG), and as such are not travelling directly for the finish line.
Nabs is in good spirits and is settling into his rowing, eating and sleeping routine.