STAND in the middle of town in Rach Gia, Vietnam's southernmost port, stare out into the Gulf of Thailand and you cannot tell the ocean from the sky. Under a high sun, the horizon just melts into grey as a vast slick of fish waste appears to stretch out to sea beyond sight. Out of the murkiness, three boats appear. One is listing heavily, another appears to have survived a fire, its hull and cabin blackened and still smoking. A third limps back to port, having suffered engine breakdown and lost its way for much of the 10 days it was at sea. Their catch already rotting, the crew ignore the crowd on the wharf and walk, staring straight ahead, to go and get drunk. Reforms have brought competition and opportunities to Rach Gia, and now thousands of private fishermen have arrived from all over Vietnam in all manner of rickety craft to make their fortune. More fish are being caught than ever before and some fishermen will make good money and be able to trade for better boats. Others worry they will fall prey to bad deals with the traders and middlemen who cruise in their wake, or lose limbs in accidents using dynamite illegally, a practice reportedly on the increase. A few more will succumb to the alcohol and heroin that so often fuels life on the waterfront in port towns such as this. But all who go to sea here face another problem, the threat of Thai fishermen and patrol boats allowed to operate far offshore in overlapping territorial waters. 'We see the Thai boats everywhere out there,' said Diep Minh Xuan, a 42-year-old captain, as he waited at the wharf for blocks of ice to be loaded into the hull of his simple nine-metre boat before a two-week jaunt. 'Like us, they must go further to get the big catches. Everyone is in competition and surely there cannot be enough fish for everyone . . . I don't know what will happen when everyone realises that. 'I'm very jealous of the Thais - their boats are big and strong and fast.' Xuan's family have fished here for generations, meaning his boat is much bigger than most. Still, like the others, radio and navigational equipment is basic, and he must hope the huge blocks of ice keep his catch of mackerel and shrimp from rotting in the remorseless sun of the Gulf. His links to the coast means he is wary of anyone - Thai or local from up country - moving in. 'We worry about the very near future. Everybody is now coming here, and with foreign money, the boats will finally get bigger and better so I think the stocks will really start to die soon. The fishermen from outside, they come here and they say: 'there will always be fish in the Gulf' - no wonder we are in trouble.' With increased numbers of boats in the Gulf, the recent past has seen both the Thai and Vietnamese sides detain fishermen and boats, fuelling a string of offshore incidents between rival fishermen. Such an atmosphere sparked joint talks between senior officials in March in Phuket which called for peaceful co-existence within overlapping offshore zones. Last week's shootout showed just how tenuous that peace is. Two Vietnamese and one Thai were shot dead in a 30-minute shootout between rival patrol boats some 130 kilometres east of Songkla in southern Thailand, as Vietnamese provincial border defence vessels escorted what Hanoi claimed was a wayward Thai fishing fleet. Vietnam claims the Thai navy attacked first while the Thai Foreign Ministry insists its craft reacted only after coming under fire from 40mm Vietnamese cannons. Both sides - whose official friendship is soon to be boosted by Vietnam's membership of ASEAN (Association of Southeast Asian Nations) next month - quickly pledged peace. But as officials in Bangkok and Hanoi sift through the diplomatic debris of last Wednesday's violence, it is clear the stakes are high, with fishing increasingly important for Vietnam. As Xuan fears for the future, the local government in Rach Gia is eagerly seeking foreign investment to add much-needed value to vastly increased catches. Senior administrator Lam Quang Chanh said 6,000 boats were now licensed to work out of Rach Gia, the capital of Kien Giang province. The craft, most just 20 horsepower and a little bigger than sampans, are catching 50 per cent more fish than three years ago, with more than 170,000 tonnes to be produced this year. The catch hauled into Rach Gia account for 10 per cent of Vietnam's national catch and is expected to reach more than US$500 million (HK$3.9 billion) in exports this year - the country's second-largest foreign exchange earner. 'We know that foreign investment is the only way for us,' Mr Chanh said.