This page explains a Nisyros boat trip through the boat itself, then the bow, the hull, the propeller, the anchor, the keel and the knot. Four answers wrap up the page, and every new term is defined where it appears. Browse more trips at Greece tours.
What is a Nisyros boat trip?
The Nisyros boat trip is an outing on a boat. A boat is a watercraft, which means a craft made to travel on water. Boats come in a large range of types and sizes. The word therefore stands for a wide range of designs.
A Nisyros boat trip page keeps the words boat and ship apart. A ship is set apart by its larger size or capacity. Its shape also marks it, as does its ability to carry boats. Capacity means how much a craft is able to hold. Those three marks separate a ship from a boat.
Small boats tend to be used on inland waterways such as rivers and lakes. Inland waterways are bodies of water away from the sea. Whaleboats were intended for offshore use, which means out on the open sea. The word boat covers both settings on a Nisyros boat trip page.
In modern naval terms, a boat is a vessel small enough to be carried aboard a ship. Naval means linked to a navy, a country’s sea force. A vessel is any craft built to float on water. Under this rule, the ship sets the size limit, and that holds for a Nisyros boat trip too.
Boats vary in proportions and construction according to purpose, materials, or local traditions. Proportions are the sizes of the parts compared with each other. A local tradition is a building habit passed down in one place. A Nisyros boat trip page treats all three as separate causes of variety.
Canoes have been used since prehistoric times and are still used worldwide. Prehistoric describes an age before people kept written records. A canoe is a narrow boat that people move with paddles. A dugout canoe is made from a single log. A log is a cut length of tree trunk.
Any boat on a Nisyros boat trip page has a hull, which is its main shell. The hull provides both capacity and buoyancy. Capacity is the space for load, and buoyancy is the power to float. A boat that is overloaded with structure, cargo, and water can ultimately sink. Cargo means goods carried on board.
A raft is buoyant because it joins buoyant components, such as logs and bamboo poles. Buoyant means able to float, and components are the parts of a whole. In colder regions, a raft is not a practical means of transport. Users there risk hypothermia, a dangerous loss of body heat.
- Safety: Lifeboats have rescue and safety functions, which means they help people who are in danger.
- Cargo: Lighters move cargo to and from large ships that cannot get close to shore.
- Materials: Ferro-cement hulls use a steel or iron wire framework covered with cement.
A Nisyros boat trip page names no single build method. Cold molding is a modern construction method that uses wood as the structural component. A structural component holds a thing together. By the 1930s, steel boats were replacing wooden boats in industrial uses and fishing fleets.
On a Nisyros boat trip, what does the bow bring?
A Nisyros boat trip opens with the bow, the front end of a boat. A bow is designed to let the hull, the main body of the boat, pass efficiently through water. Efficiently means moving with little wasted effort.
Prow names the foremost part of the bow above the waterline. The waterline is where the water meets the side of the boat. Prow and bow are used interchangeably, meaning either word names a ship’s foremost part and its surrounding parts. Either word, on a Nisyros boat trip, simply means the front.
Bow shapes vary according to the speed of the boat. Slower ships like tankers use a fuller bow to maximise volume for a given length. A tanker is a cargo ship, and a fuller bow is rounder and wider. Volume means the space inside. Tankers are one example that a Nisyros boat trip reader meets.
Where sea conditions promote pitching, a bow with reserve buoyancy is useful. Pitching is a boat’s front end rising and falling. Reserve buoyancy is extra floating power in the bow. Large commercial barges on inland waterways rarely meet big waves. A barge is a flat cargo boat; inland waterways are rivers and canals.
A flared bow is ideal for reducing the water shipped over the bow. Flared means the sides curve outward, and shipped water is sea water that comes aboard. The bow can also be reinforced, meaning made stronger, to serve as an ice-breaker. An ice-breaker cuts a path through ice.
Next on a Nisyros boat trip comes the stem, an extension of the keel itself. The keel is the main beam along the boat’s bottom. The stem is the curved edge running from the keel up to the gunwale. The gunwale is the upper rim along a boat’s side.
A stem perpendicular to the waterline is called plumb. Perpendicular means standing at a right angle to the water. A stem inclined at an angle to the waterline is called raked. Inclined means tilted. Plumb and raked are the two words a Nisyros boat trip reader needs for a stem’s angle.
Traditionally the stem was a timber or metal post joining side planks. Timber is cut wood, and a post is an upright beam. Viking longships, the long boats of the Vikings, have no straight stem and instead a curved prow. Here, a Nisyros boat trip comparison puts the post next to the curve.
- Origin: The ship word bow comes from Middle Dutch boech, an earlier form of the Dutch language.
- English: The ship sense of the word bow was unknown in English before 1600.
- Other languages: The French word for prow is proue, and the Latin word is prora.
On smaller vessels, the top of the stem can carry a wood carving or a cleat. A carving is decoration, and a cleat is a fitting that holds a rope. Anyone planning a Nisyros boat trip now has the bow, prow and stem named.
On a Nisyros boat trip, what does the hull bring?
A Nisyros boat trip page puts the hull first. The hull is the watertight body of a ship, boat, submarine or flying boat. Watertight means that no water gets in through the body. The word hull names that body for each of those craft.
The deckhouse, a built part that stands atop the deck, features on a Nisyros boat trip page. The deck is the flat top surface of the hull. Other superstructures, meaning built parts above the deck, can stand there. An icebreaker has a rounded bow, the front end. A landing craft has a flat bottom.
A Nisyros boat trip page lists the composite hull. A composite hull is built by sandwiching thin skins over a lightweight core. The skins are fiber-reinforced, meaning fibers add strength to them. The core is the light layer between the skins. That core can be foam, balsa wood or impregnated paper honeycomb.
A Nisyros boat trip page groups hulls primarily into two families. Chined hulls have a chine, the sharp line where the side meets the bottom. The other family is moulded, round bilged or soft-chined hulls, where that join is curved. The round bilge hull is the form in widest use at present.
A flat-bottom chined hull has high initial stability but high drag. Initial stability is how steady the hull feels when it first tilts. Drag is the resistance water offers to a moving hull. A multi-chine hull, one with more than one chine, approximates a curved hull form. It comes close to a curve.
A Nisyros boat trip page defines planing, which is skimming across the surface rather than ploughing a path. A planing hull has at least one chine, which makes planing more efficient. Dynamic lift on a planing hull cuts its wetted surface and so reduces drag. The wetted surface is the part touching the water.
The displacement hull stands apart on a Nisyros boat trip page. It is supported mainly by buoyancy, the upward push that water gives a floating object. Displacement is the weight of water equal to the hull’s immersed volume. The immersed volume is the part of the hull that sits under the water.
A keel on a Nisyros boat trip page is a fitted part. A keel can be fitted to increase transverse stability, directional stability or lift. Transverse stability is steadiness from side to side. Directional stability is steadiness on a straight line. A hull can also carry trim tabs or stabilizing fins as control devices.
- Planing speed: Planing hulls are more efficient at higher speeds but need more energy to reach them.
- Moulded depth: Moulded depth is measured from the keel’s top to the underside of the upper deck.
- Beam: Beam is the width of the hull, and breadth is another word for it.
Computer-aided design has replaced paper-based ship design methods that used manual calculations, meaning sums worked out by hand. Since the early 1990s, ship design software has offered 3D drafting with hydrostatic calculations. Hydrostatic calculations are sums about how a hull floats in water.
On a Nisyros boat trip, what does the propeller bring?
A Nisyros boat trip leads first to the propeller, a set of spinning blades. The blades push water backward, and the boat moves forward. The story runs from early submarines and ships to safety parts, blade shapes and damage by bubbles.
The propeller story behind a Nisyros boat trip starts in the year 1775. In New Haven, Connecticut, David Bushnell designed the submarine Turtle that year. A submarine is a boat built to travel under water. A designer draws the plan of a craft before anyone builds it.
The Nisyros boat trip page moves on to an attack with that submarine. On September 6, 1776, Sergeant Ezra Lee piloted Turtle in an attack on HMS Eagle. To pilot a craft means to steer and control it. HMS is the title placed before the name of a British navy ship.
Planners of a Nisyros boat trip meet Josef Ressel next. His 48-ton ship Civetta reached 6 knots. A knot is a speed of one nautical mile an hour. A nautical mile is a distance measured at sea. Weight at sea is counted in tons, so 48 tons tells how heavy the ship was.
Ressel also has a setback in his story. Police banned his propeller experiments after a steam engine accident. A steam engine is a machine that uses hot steam to make parts move. An experiment is a test made to find out how something works. An accident is a sudden event that causes harm.
A Nisyros boat trip page also names John Patch, a mariner from Nova Scotia. A mariner is a sailor. In 1832, Patch developed a two-bladed propeller. A blade is the flat arm of a propeller that pushes the water. Two blades mean two such arms on one propeller.
A reader of a Nisyros boat trip page finds a tale about Smith’s propeller too. The propeller broke, and what remained was only a single turn. A turn is one loop of the spiral blade. That broken propeller doubled the boat’s speed to about eight miles an hour. A mile is a unit of distance.
Another example on a Nisyros boat trip page dates from 1802. John Stevens built a 25-foot boat with a four-bladed propeller. Boat length is counted in feet, so 25 feet is the distance from end to end. With four blades, the propeller has four arms to push the water.
- Shear pin: Smaller, older engines tend to use a narrow pin that breaks under a load threatening the engine.
- Drive sleeve: Modern propellers swap the rubber ring for a hard plastic-like insert that fails first when overloaded.
- Rim-driven thruster: An electric motor built into a tube-ringed propeller needs no shaft, the turning rod, and weighs less.
Cavitation is the forming of bubbles in the water around a fast blade. It can waste power, create vibration and wear, and damage the propeller. Vibration is fast shaking, and wear is slow damage from use. Power is the energy the engine sends to the blades.
On a Nisyros boat trip, what does the anchor bring?
A Nisyros boat trip depends on its anchor, a device normally made of metal. It secures a vessel to the bed of a body of water. A vessel is a boat or a ship. Anchors can be either temporary or permanent.
Permanent anchors form a mooring and are rarely moved. A mooring is a fixed place where a vessel stays tied up. Vessels carry one or more temporary anchors. A temporary anchor is not fixed in place for good. On a Nisyros boat trip, these two kinds are easy to tell apart.
A sea anchor is a drag device that limits a vessel’s drift. Drag is a pull that slows movement. A sea anchor does not touch the seabed, the floor of the sea. A drogue is another drag device. It slows a vessel or helps steer it while the vessel runs before a storm.
Holding ground is the area of sea floor that holds an anchor. Holding here means keeping an anchor in place. An anchor grips well in hard sand, but it grips badly in shell. A Nisyros boat trip page can set sand beside shell, since the two floors hold so differently.
Anchors hold by hooking into the seabed, by weight, or by both. Hooking means catching into the bottom. Weight means the anchor holds by being heavy. In good holding ground, an anchor can dig in, and its holding power can be significantly higher. Holding power is how strongly an anchor grips.
The rode is the line that connects the vessel to the anchor. A rode can be made of rope, chain, or a combination of both. A chain is a line of linked metal rings. A Nisyros boat trip page treats cable and warp as other names for the rode.
Shortening the rope until the vessel is directly above it breaks an anchor out of the bottom. Breaking out means pulling the anchor free. Anchors are sometimes fitted with a trip line so they can be unhooked from underwater hazards. This Nisyros boat trip page lists both ways to free an anchor.
Rock anchors have been found dating from at least the Bronze Age. The Bronze Age was a time long ago, early in human history. Ancient Greeks used baskets of stones, sand sacks, and lead-filled logs as ship weights. A reader planning a Nisyros boat trip can see how old the anchor idea is.
- Admiralty pattern: A central shank, the main bar, has a ring or shackle for attaching the rode.
- Flukes: These pointed iron teeth are how an anchor grips the sea floor.
- Scope: This is the ratio of rode length to water depth, which compares the two lengths.
The word anchor derives from Latin ancora, which itself comes from Greek. Ancora is the Latin word for anchor, and Latin is an ancient language. A Nisyros boat trip planner can keep that root as a simple memory aid for the whole page.
On a Nisyros boat trip, what does the keel bring?
A Nisyros boat trip rests on the keel. It is the foundation member around which a ship hull, its main body, is built. Under sail, the keel can act as an underwater foil, a wing-shaped fin, that reduces leeway. Leeway is sideways drift.
A Nisyros boat trip story can open with the word keel. Keel comes from Old English and Old Norse words meaning ship or keel. Both are early languages. Carina is the Latin word for keel and the origin of the term careen. To careen means to clean a keel and the hull in general.
The Nisyros boat trip page can show that keel is an old word. Gildas recorded it as cyulae in his sixth century Latin work, De Excidio. He was referring to the three ships the Saxons first arrived in. The spelling looks very different today, yet the word is the same.
Keels have been used in sailing vessels since antiquity, which means ancient times. Sailing vessels are ships driven by sails. The Uluburun shipwreck, around 1325 BC, had a rudimentary keel. Rudimentary means basic and simple. That makes the keel an ancient part of ship design, worth knowing before a Nisyros boat trip.
In carvel-built hulls, a boat-building style, construction began with laying the keel, then the stern and stem. The stern is the rear end of the ship, and the stem is the front end. Frames were then set up at key points along the keel. Frames are the ribs of the hull.
Later, the keelson was attached to the keel by bolts or treenails. A keelson is a reinforcing timber, and treenails are wooden pegs. Clinker construction, a plank-first method still in use, uses overlapping planks. Planks are long flat boards. On a Nisyros boat trip, overlapping planks are easy to picture as layered boards.
Large modern ships are now built from prefabricated hull sections, not around one keel. Prefabricated means made in advance. A hull section is a piece of the ship body. A series of them makes up the whole hull. The Nisyros boat trip page can set this beside the older carvel method.
The flat plate keel is fitted in ocean-going ships and other vessels. Ocean-going means sailing on oceans. With a double bottom fitted, the keel is almost inevitably a flat plate type. A double bottom is a hull base with two layers. The Nisyros boat trip page can link hull design to keel shape.
- Position: The keel runs along the ship centerline, from the bow at the front to the stern.
- Bar keel: A bar keel can be fitted to trawlers (fishing boats), tugs (towing boats), and small ferries.
- Bilge keel: A bilge keel lets a sailboat sit on mud, sand or shingle (small stones) to dry out.
Heel is the lean of a boat to one side. The angle of heel is how far the boat leans. The heeling moment is the turning force that tips the boat over. A keel offsets that moment more as the angle of heel grows.
On a Nisyros boat trip, what does the knot bring?
A Nisyros boat trip page opens on the knot, a unit of speed. The knot is exactly 1.852 kilometres per hour. A kilometre is a unit of distance, and per hour means for each hour that passes. That gives one fixed value.
The knot is used in meteorology, maritime navigation and air navigation. Meteorology is the study of weather. Maritime navigation means finding a way across the sea. Air navigation means finding a way through the sky. A Nisyros boat trip planner can learn one unit that all three fields share.
A meridian is a north-south line on a globe. Latitude is a place’s north-south position on a globe. In an hour, a vessel at one knot on a meridian shifts its latitude by about one minute. A planner of a Nisyros boat trip can read that as speed becoming a change of place.
The internationally agreed nautical mile is 1852 metres long. Nautical miles and knots are convenient units for navigating an aircraft or ship. The nautical mile behind the knot is closely tied to the latitude-longitude system. That system names a place with two coordinates, which are numbers that fix a spot on a globe.
The chip log was an old way to find a vessel’s speed. Knots tied 47 feet 3 inches apart passed through a sailor’s fingers. A sand-glass is a glass timer that runs on falling sand. The currently accepted timing used a 28-second sand-glass. A Nisyros boat trip page can file the chip log under history.
By the chip log method, one old knot measured 1.85166 kilometres per hour. That old value differs from the modern knot by under 0.02%. A percent is a share out of one hundred, so the gap is very small. For a Nisyros boat trip plan, the two values count as almost the same.
The international nautical mile definition was adopted by the United States in 1954. The United Kingdom did the same in 1970. Before 1970 the UK used the Admiralty nautical mile, which was 6080 feet long. A Nisyros boat trip page can list these two dates as steps toward one shared definition.
A nautical chart is a sea map, and on a Mercator one the east-west scale changes with latitude. Speeds of boats and aircraft relative to the fluid they travel in can be given in knots. A fluid is water or air. True airspeed, or TAS, is an aircraft’s speed relative to undisturbed air, in knots.
- Miles: A mile is a distance unit, and one knot is about 1.151 miles per hour.
- Metres: A second is a short span of time, and one knot is about 0.514 metres per second.
- Abbreviation: The International Civil Aviation Organization recommends kt, the form used in aviation.
In 1969, aircraft standards began to specify distances in nautical miles and speeds in knots. A standard is an agreed rule that everyone in a field follows. A Nisyros boat trip page can end on that date.
Which four questions matter before a Nisyros boat trip, and how are they answered?
A Nisyros boat trip page answers four everyday questions in plain words. They cover the season, the time zone, the currency, and the spoken language. Each answer rests on three sourced facts, so a planner gets short, checkable replies.
Which season suits a Nisyros boat trip?
A World Meteorological Organization weather station in Gytheio, in the Peloponnese region, registered 46.4 °C. The Dodecanese, a cluster of islands belonging to Greece, has local winter averages above 15.0 °C. In this Mediterranean climate zone, the west areas get relatively more precipitation, meaning rain and snow.
Which time zone applies behind a Nisyros boat trip?
Eastern European Time is also called GTB Standard Time for Greece, Turkey and Bulgaria. A number of African countries keep UTC+02:00 year-round, as Central Africa Time. UTC+02:00 sets clocks two hours in front of Coordinated Universal Time. Turkey used Eastern European Time in 1910–1978 and again in 1985–2016.
Which currency is used behind a Nisyros boat trip?
The euro is written with the symbol € and carries the code EUR. A code of this kind is a short group of letters naming one currency. One euro splits into 100 cents. The euro entered world financial markets as an accounting currency on 1 January 1999. An accounting currency is a unit for keeping financial records.
Which language is spoken behind a Nisyros boat trip?
Greek is native to Calabria and Salento in Italy. Greek has at least 3,400 years of written records, the longest of any Indo-European language. Indo-European is a large family of related languages. The Hebrew Bible was translated into Koine Greek, a form of Greek. That translation is known as the Septuagint.