The terms `Surat` and `Udaygiri` in the context of India`s defense refer to warships. Warships are naval vessels that are specifically designed and equipped for combat operations at sea. They play a crucial role in protecting a country`s maritime interests and ensuring its security.

Option 1: Coast guard patrol boats are used by the coast guard for patrolling coastal areas, enforcing maritime laws, and conducting search and rescue operations. While they also contribute to maritime security, they are distinct from warships.

Option 2: Cargo helicopters are aircraft specifically designed for transporting goods and supplies. They are primarily used for logistical purposes and not directly related to defense operations.

Option 3: Maritime patrol aircraft are used for surveillance, reconnaissance, and anti-submarine warfare in maritime environments. While they are important for naval operations, they are not warships.

Therefore, the correct answer is option 4, warships, as they are the vessels referred to by the terms `Surat` and `Udaygiri` in India`s defense context.