Why Boats Float

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Why Boats Float

• Haul Design and Stability

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Archimedes
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Archimedes (287? -212B.C.)

• Archimedes is considered one of the three
  greatest mathematicians of all time along with
  Newton and Gauss. In his own time, he was known
  as "the great geometer" and his works and
  inventions brought him fame that lasts to this
  very day. He was one of the last great Greek
  mathematicians.

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Archimedes Principle

• when an object is partially or fully submerged,
  the buoyant force, or apparent loss in weight, is
  equal to the weight of the fluid displaced.

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Why Do Heavy Boats Float
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Boat Stability
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Bad Boat Stability
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Different haul Designs

• Mono Haul
• Catamaran
• Mono Haul Sailboat
• Hydrofoil
• Airboat or Flat Bottom
• Hover Craft

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Mono Haul Boats
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Mono HaulBoats

• Mono-Haul boats are single hauled mono
• and are the most common design. Used in most
  recreational vessels and sail boats.
• The reason this haul design is so common is it
  one of the oldest designs and is very efficient
  in transporting both passenger and goods.

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Catamarans

• Catamarans- are a dual hauled vessel commonly
  wind powered but can be powered by a combustion
  engines

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Benefits of Catamarans
The benefits of catamarans is that the wider
stance of a catamaran allows for more stability
and smaller volume hauls cause less drag and
allow for greater speeds
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Sailboats

• Sailboats are commonly a mono-haul boat but can
  be found in bi and tri-haul designs.
• Sailboats have been used for a long time do to
  there efficient use of the wind to power them.
• Do to the use of the wind and the common
  mono-haul design sailboats make use of a long
  heavy rudder like piece in the center of the haul
  called the keel.

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Hydrofoil
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Hydrofoil Design

• Hydrofoils are superior to conventional haul
  design in the fact that the haul it self is out
  of the water while the vessel is in motion.
• The vessel is lifted out of the water with the
  use of the foil which is a wing under the water
  that acts like an airplane wing in the idea of
  Bernoullis Principle and creates lift with a low
  pressure on the top side creating a high pressure
  below.

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Air Boat or Flat Bottom
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Airboats

• Airboats are designed with a wide flat bottom so
  that there is very little drag. Also so that
  very little of the haul is submerged.
• The Benefit of this design is that the boat is
  capable of going virtually any where with a
  little bit of cushion as shown.
• The negative aspect of the airboat is that there
  is very little steering capability do to neither
  haul nor prop are in the water.

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Hovercraft
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Hovercraft

• Hovercrafts are much like air boats in that the
  have very little steering ability and that little
  of the haul is in the water.
• On the hovercraft the haul would be the
  skirt/air. This would be considered superior to
  the traditional haul because it does not require
  water to be displaced for the air makes up the
  distance.

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Reference

• http//www.boatsafe.com/kids/021598kidsques.htm
• http//www.spartechsoftware.com/reeko/ScienceTips/
  SciTipFloatation.htm