Nigel Dennis says he has lost at least £20,000 because of the weakening dollar.
Nigel Dennis Kayaks exports 350 crafts a year to the US
Mr Dennis, whose Anglesey-based firm sells kayaks to the US in dollars, is finding the money he gets is worth less than last month.
"The whole export market is being affected, and we are not making as much money as we used to," he says.
"I have never know anything like this. The dollar has been up and down, but now it has been going in only one direction for a long time.
"This is the first time I have seen a prolonged dive like this one."
Mr Dennis, who has been exporting to the US for eight years, employs 11 people at his premises in Holyhead.
He says his firm sells 350 kayaks, retailing at roughly $3,000 each, every year to the middle-class market on the US east coast.
"We have not lost any orders, because as we invoice our customers in dollars it makes no difference to them.
"If we were invoicing in sterling we would be losing customers, but obviously it would help us if the dollar is stronger than it is at present."
Mr Dennis says he hopes the exchange situation did not get "more serious".