Factors affecting the actual value of squat will vary considerably but could expect to include any or all of the following:
- Draught/depth of water ratio. A high ratio equates to a greater rate of squat.
- The position of the longitudinal centre of buoyancy (LCB) will determine the trimming effect and have a direct relation to the squat value.
- High engine revolutions can expect to increase stern trim.
- The speed of the vessel is related to the value of squat in that the value is influenced by speed.The faster the ship moves the greater the squat value.
- The type of bow fitted effects the wave making and pressure distribution on the under water volume.
- The length/breadth ratio can cause an increase or decrease of the squat value, i.e. short-tubby ships tend to squat more, than the longer narrow beam vessel.
- The breadth/channel width ratio affects the squat value. A high ratio causing an increased value of squat.
- Vessels with a large block coefficient Cb will experience greater effects from squat.
- Greater effects of squat are experienced when a vessel is trimmed by the bow than by the stern.
- Ship’s speed (Main Factor). Squat is directly approximately proportional with the speed squared.
- Depth of water: inversely proportional.
- Confines of the channels: inversely proportional.
- Block Coefficient (ratio of the immersed volume of the ship relating to the water line length, breadth and draft): directly proportional.
- Blockage Factor (immersed cross-section of the ship’s mid-ship section divided by the cross-section of the canal or river): directly proportional.