Whaling, in the age of sail, could be very profitable. Although a lot depended on luck and skill in finding and catching whales.
The Charles W. Morgan, is a New England sailing whaling ship, launched in 1841 for a cost of $27,000. (All up cost, once fully rigged, outfitted and equipped, was $ 52,786.) (Still afloat today as a museum ship (recently refurbished and seagoing again) in Mystic Seaport, Connecticut.)
By the time she finished her last commercial whaling voyage, in 1921, the “Morgan” had earned $1.4 million from the 54,483 barrels of whale oil she sold as a result of 37 whaling trips.
In 1851, the New Bedford whaler, “Benjamin Tucker”, made an after expenses net profit of $45,320. The crew split between $13,500 and $18,200. The owners got the rest.
When the whale ship “Milton” returned to port in 1836, she made a profit of $99,994. The captain got $5,882, the first mate got $4,545, the boat steerers $1,333, the blacksmith $714, the best paid seamen $800, the worst paid seamen $571. The owners would have more than paid for the whole cost of the ship in one cruise.
(It is very difficult to compare the money made by the "Milton" crew in 1836 to money today. A straight inflation index adjustment would indicate that the captain earned about $60,000, in today's money - which does not seem that much for a three year voyage. If we compare the captain's earnings to the average income then, however, and then calculate what that would be compared to the average earnings today, we get something like $600,000, which seems more worthwhile. (Especially as there were no income taxes to come out of it back then.))
That was a good voyage. The “Milton” made another whaling cruise which was a real dud where the worst paid ordinary seaman made only $10.10.
The history of the “Charles W. Morgan”, illustrates that even though she never made any block-buster cruises, an average whaling ship was a pretty good investment for its owners. (Though the “Morgan” had an unusually long life.)
The history of the “Tucker” and the “Milton” illustrate that the returns from whaling could be highly volatile, with the prospects of possibly really striking rich, or of having a poor cruise with disappointing returns.
http://www.whalingmuseum.org/learn/research-topics/overview-of-north-american-whaling/whales-hunting