They were fishing for trepang and appeared to have only a small compass as a navigation aid.
From the en.wikipedia.org
The typical dishes on local menu are braised abalone, braised trepang, sweet and sour carp, Jiuzhuan Dachang and Dezhou Chicken.
From the en.wikipedia.org
Later he assisted the Yapese in acquiring rai and in return received copra and trepang, which were valuable exports in the Far East.
From the en.wikipedia.org
A former prawn trawler, and later trepang vessel, has been sunk off the Darwin coast, adding to the Northern Territory's abundant artificial reef system.
From the ntnews.com.au
Makassan traders began trading with the indigenous people of the Northern Territory for trepang from at least the 18th century onwards, and very likely for 300 years prior to that.
From the en.wikipedia.org
Macassan traders from Sulawesi regularly visited the coast of northern Australia to fish for trepang, an edible sea cucumber to trade with the Chinese since at least the early 18th century.
From the en.wikipedia.org
More examples
Of warm coasts from Australia to Asia; used as food especially by Chinese
A sea cucumber of the southern Pacific and Indian oceans, dried or smoked for use as an ingredient in soup.