when does a boat capsize?

Question

what makes a boat capsize? and how can you avoid this?

Answer 1

You have some practical answers given, but you probably knew that taking waves from the side left you more vulnerable to capsizing than if you pointed your bow into the waves; I'm assuming that you were asking for the theoretical answer.

When a ship rolls (side to side rocking motion) it tends to right itself to an fully upright position once the wave motion causing the roll dies down. The reason this happens has to do with the righting arm of the vessel. The righting arm will vary with the shape of a hull and weight distribution. Righting arm calculations take into account the center of buoyancy of the boat (that's the shape of the hull dependant part) and the center of gravity of the boat (the weight dependant part.)

When a boat is totally upright the center of gravity and the center of buoyancy are on "the same line." The two forces - gravity downwards and buoyancy upwards - are acting in line and the vessel is in equilibrium. When the boat rolls the center of buoyancy shifts - since the shape of the submerged hull has changed. (Not the shape of the hull, but the shape of the part displacing water.) Since the center of gravity doesn’t move and it still acts downwards (towards the center of the earth) and buoyancy still acts upwards a moment is caused, this is the righting action.
When the boat rolls so much that vessel begins taking on water over the side the center of gravity will change, and down flooding or capsizing will result. A poorly designed vessel may reach the limit of its righting arm before this point, and become inherently unstable. If the buoyant force isn't enough to "push the boat back up" to an upright position the boat will also capsize.
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Answer 2

You only need to worry about capsizing if you are on a power boat or a multi hull sailing boat, because a single hull yachts are desigened to stand back up from laying on their side, you just need to let all of the sheet ropes off and it should stand back up.

To avoid capsizing a power boat (a smaller craft) make shure that it is weighted fairley evenly, and that you are not taking the waves side on, although in some situations this can not be helped.

Some of the larger crusers now have things in them to help prevent them from capsizing, an example of this is Sunseeker.

The answer from science teacher about a yacht was wrong that it is healing because it can not put all of it's motion to move forward, so it heals. This is not right, I sail and if you are going up wind you have to keep the boat healing over an ammount or you will slow the boat down, or even stop moving (this is based on yachts 20 feet and bigger)

Answer 3

A boat capsizes when the heeling forces are greating tha he righting moment. A boat with a keel has more righting moment. Weight in the keel keeps it from capsizing. They used to say 40% of the weight of the boat should be in the keel.
Sailing, if there is more force into the sails than the boat can convert to forward motion in time it heels, possibly enough to take on water. Be ready to release the sail to let off the heeling force. Head into waves at an angle to the bow. Watch the weather .

Answer 4

hers a simple answer you get top heavy and tilt then its over and capsized most navy cost guard and river tugs are capsizeable i guess you could say then they can right themselves.

Answer 5

Human existence can't be in comparison to animal existence. i admire animals and abhore animal abuse and poaching. Clubbing those infant seals is terrible, yet you very almost look ok that those adult adult males drowned. Any loss of human existence is an entire tragedy, yet they did no longer should die for it. it type of feels as while you're "HA HA-ING" at them.

Answer 6

taking a swell from the side. Aim the bow into the waves.

Answer 7

boat capsize when it is not balance...so keep it balanced

Answer 8

when in rough weather you lose power and/or steerage. the main cause is operator error. not necessarily that the operator doesn't know how to avoid it but he just makes the wrong judgement call at the wrong time. to avoid it you must first have knowledge and secondly "the grace of God".