A Big Dir

Many types of boats that we meet today, some have a hull only (monohull), some have two hull (catamaran) and some have three hull (trimaran).

Whether it's monohull, catamaran or trimaran basically categorized in 3 based on the type of hull form below the surface of the water line, yaitu Displacement hull, semi displacement hull/semi planning dan planning hull.

Displacement hull

Displacement hull boat is moving on the surface of the water itself weighing boat (weight of water displaced as heavy boat), then to get the maximum speed of the submerged hull forms in the water from the front to the back is a streamlined, and the cross-section at the bottom of the water was made round. It is intended to reduce frictional resistance and wave resistance at the surface of the water speeding boats.

There is 2 macam tipe displacement hull, namely :

Heavy displacement : boats that are used for heavy work on the stern boat, like a tug boat and a boat deep sea trawlers.

Medium displacement : these boats are commonly used for this type of displacement hull or not to work pull heavy loads, seperti pleasure boats, fishing boats, sail boat, yachts and other.

Type displacement hull boats allocated to a low speed (froude number < 1.4).

Excellence Displacement hull is small engine power, so that fuel consumption is much lower. Small engines means the cost of buying and maintaining a lighter, besides these boats tend to be stable and comfortable while anchored to relax by the sea.

Planning Hull

Type of planning hull boats are moving on the surface of the water at high speed so that the water displaced is not heavy boat body itself due in part to the front of the hull lifted, so the barrier below the surface of the water into a small.

With a high-speed course requires a large power, Great power requires great fuel consumption too, so the type of boat is arguably very expensive. In Indonesia, most types of boats are owned by the government and military for patrol needs, inspections and the like, As for the personal usually for the purposes of recreation and beach sports such as fishing boat, pleasure boat dan power boat.

Type of planning is that from year to year changes and significant progress for the world maritime.

A generic term for the type of planing we know is: Moderate V dan Deep V . Moderate V, at the transom deadrise angle ranges 15 degrees to 19 derajat. While Deep V, at the transom deadrise angle of 20 to 24 derajatdegree

Semi displacement hull/ Semi Planing

Semi displacement / semi-planning hull is halfway between displacement and planning hull type.

In the semi displacement / semi-planning hull with a maximum speed of the front can be lifted up, This depends on the value of Froude and hull shape itself.

To get a good speed / maximum with good stability usually in the V-shaped boat bow and at the stern shaped somewhat flat and there is also a rather round-shaped.

&nbsp;Stability

Sari three types mentioned above which have the best stability is the type of planning hull, because it has a point value of GM or large metacentric. But in terms of comfort of displacement type hull which has particularly best comfort.

Parameter

Speed ​​/ length ratio or Froude number is known as one of the parameters that can be used as a consideration in choosing the type of hull that is appropriate for the needs of :

• Displacement hull, nilai speed/length ratio (kn/ft^1/2)no more than 1.4
• Semi-planing hull, nilai speed/length ratio antara 1.5 to 2.0
• Planing hull, nilai speed/length ratio diatas 2.0

Length is the length of the waterline boat (Lwl)

Tips

For those who want to buy a motor boat there are a few tips that will make you not disappointed. Because the motor boats right (blend of speed comfort and stability) very expensive, while very difficult to resell.

• See the parameters mentioned above, so know exactly what type of boat you need, both in terms of the need for speed, comfort, fuel consumption or costs relating to the condition of the waters and even the function of the boat that will be used, so we get a boat that is ideal for us.
• Ask stability calculation and computation speed - horsepower of boats that you will buy because in our country there are many traditional companies who build boats based on tradition (habit) and experience, not based on an appropriate calculation in terms of stability and power calculation engine takes a boats. Unseaworthy boats is said in terms of stability when he meets the criteria given by the IMO (International Maritime Organization)
• Check the credibility of the company's boats.
• Safer accompanied by one who knows (expert) on boats.
• Boats Insure you buy.