What are major IMO amendments with their Date of enforcement?

New requirements in the revised Annex I include the following:

• Regulation 22 Pump-room bottom protection: on oil tankers of 5,000 tonnes deadweight and above constructed on or after 1 January 2007, the pump-room shall be provided with a double bottom.
• Regulation 23 Accidental oil outflow performance – applicable to oil tankers delivered on or after [date of entry into force of revised Annex I plus 36 months] 1 January 2010; construction requirements to provide adequate protection against oil pollution in the event of stranding or collision.

Oman Sea – new special area under MARPOL Annex I
The Oman Sea area of the Arabian Seas is designated a special area in the revised Annex I.