Consider the following statements: 
1) A braced cofferdam is used in shallow trench excavation as well as in deep excavation exceeding 6 m in depth. 
2) Cofferdams, braced or un-braced, are temporary structures either on land or in water bodies. 
3) When sheet piling is used for retaining soil, or soil and water, without any bracing, it is called a bulkhead. 
Which of the above statements are correct?