A dispute over the passenger Jones Act has Southeast Alaska yacht captains crying foul

Giant, gleaming yachts make their way to Southeast Alaska every summer. Many line the breakwater at Juneau's Statter Harbor. More anchor out in Auke Bay.

Some are the playthings of billionaires. Others, despite their opulent touches, are small family businesses, which are facing growing competition from new entrants they accuse of skirting a 140-year-old federal law meant to protect U.S. shipbuilders, vessel owners and mariners.

The Dauntless, a $1.65 million motor yacht owned and operated by the husband-and-wife team of Alisa Jestel and Jim Edgars, falls into the latter category. Aboard, it l...