Constructing a canal across the Kra Isthmus in Thailand would create a direct passage between the Gulf of Thailand and the Andaman Sea. This shortcut would significantly reduce shipping distances and transit times for vessels traveling between the Indian Ocean and the South China Sea, bypassing the longer route around the Malay Peninsula. While deepening the Malacca Strait would improve navigation, it would not offer the same level of distance reduction as a direct canal across the isthmus.