Local gold, nickel and iron ore miners are all nervously watching the rise in the currency this year.

But coal shippers are facing the double whammy of softening US-dollar coal prices and a strengthening local currency, says Macquarie Equities analyst Frank van Rooyen.

"Export coal stocks are heavily impacted as coal prices are coming off, so their margins were under pressure anyway," van Rooyen told MiningNews.net.

Two years ago thermal coal prices were high and the Australian dollar was nearer US50 cents, resulting in robust margins for the handful of local coal producers.

"Now their margins are being squeezed quite badly," van Rooyen said.

The Australian dollar was steady Wednesday at around US64.55 cents.

But earlier this week it soared to its highest level since January 2000 with a peak of more than US65 cents.

Reflecting the local dollar’s charge, Macquarie has revised its long-term exchange rate assumption upward to US68 cents.

Using that rate, Macquarie calculates that Macarthur Coal and Austral Coal will be two of the most heavily impacted junior rock kickers.

Macarthur Coal was down 2 cents at $1.10 today, a far cry from its level of around $1.50 at the start of the year.

Austral was 0.5 cents firmer at 49 cents – well short of its January levels of 60 cents-plus.