The term 'clumsy boat' can refer to four different types of vessels: a TUB, HULK, SCOW, and ARK. A TUB is a small, round boat that is often used for recreational purposes. A HULK is a large, unwieldy vessel that is usually used for cargo transport. A SCOW is a flat-bottomed boat with a shallow draft, making it suitable for shallow waters. Finally, an ARK is a large, open boat that is typically used for transporting goods or passengers. All of these boats are considered clumsy due to their size and shape, which makes them difficult to maneuver.