Fancy a Swim?

Until Big got sick, Luk Koong gave his job little thought. At least four times a day for the past 15 years, the stocky Bangkok resident has stripped off his tattered shirt, donned a pair of antiquated goggles and slipped into the murky waters of one of the capital's klongs, or canals, to untangle debris from the propellers of riverboat taxis. The service takes no more than 10 minutes and nets him $2.50 for each dive. Luk Koong, 33, who was raised on the klongs and whose nickname in Thai means "shrimp baby," considered it easy money.

Until...