Consider the following statements related to field and underwater archaeology:

1. Archaeological regional surveys are conducted by walking through specific sections of land, recording surface features and artifacts found on site.
2. Archaeologists primarily work on land-based sites, with underwater archaeology being a less developed area in most regions.
3. Underwater archaeology integrates the expertise of professionals from disciplines such as oceanography and geology.
4. Notable underwater archaeological finds have been recently uncovered off the coasts of Dwarka and Bet Dwarka in Gujarat (Sundaresh et al. 2002).

Which of the following statements are correct?