• speed reduction, whether enforced or voluntary to reduce motions.

The naval architect will select a form judged to provide good seakeep-ing characteristics. Stabilization can be used to reduce roll if desirable.


Manoeuvrability is not too important for a ship in the open ocean. In restricted waters it can be critical. Stopping distances of the huge super tankers are very large. Astern power must be adequate to give the desired deceleration. A balance must be struck between giving a ship very good manoeuvrability and relying upon tugs for assistance in port. What is meant by good manoeuvrability and means of providing it in a ship are discussed under Manoeuvring (Chapter 13). Twin shafts, azimuthing propellers and lateral thrust units are some of the means used to obtain good manoeuvrability. These cost money and the cost must be set against the cost and delays of using tugs, remembering a tug may not always be available when needed. Ferries which frequently berth and unberth will normally be designed to operate without the assistance of tugs except in exceptional weather conditions. For long haul ships providing a high degree of manoeuvrability could be uneconomic.

Floating oil drilling rigs require exceptionally good performance in maintaining their position relative to the ground and for that reason they are provided with dynamic positioning systems. A series of thrusters under computer control are constantly correcting the position against the effects of wind, current and waves. In such vessels fin stabilizers are of little use for reducing roll and some form of tank system would be fitted if needed. Mine countermeasure ships also need to be able to maintain an accurate path over the ground if a suspected minefield is to be swept with the minimum number of passes and in maximum safety.

How To Have A Perfect Boating Experience

How To Have A Perfect Boating Experience

Lets start by identifying what exactly certain boats are. Sometimes the terminology can get lost on beginners, so well look at some of the most common boats and what theyre called. These boats are exactly what the name implies. They are meant to be used for fishing. Most fishing boats are powered by outboard motors, and many also have a trolling motor mounted on the bow. Bass boats can be made of aluminium or fibreglass.

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