Underwater archaeologist, Dr Lee Spence, is investigating the wreck of the SS Ozama – built in Leith in 1881 and owned by a firm called Walker, Donald and Co in Glasgow.
Dr Spence, 65, hopes to salvage cargo and gold from the ship, which he located five miles off Cape Romain, South Carolina.
Dr Lee, who has been hunting shipwrecks for 50 years, said: "She is in far better condition than I would ever have expected for a vessel of her type and age.
"We are not planning to raise the vessel. She is 216ft in length and way too big.
"However, we plan to salvage any cargo or gold that we find on her."
The steamer, originally named Craigaillon, was wrecked in the Bahamas in 1885. She was later salvaged by a Norfolk, Virginia company before being towed to Baltimore, which is how she came to be owned and registered as an American vessel and named SS Ozama.
Later, she sailed back to Glasgow and was used to transport weapons to Haiti in 1888, when General Louis Hyppolyte was making a play for power.
He served as President of Haiti from 1889 until 1896.
Newspaper reports from the time describe SS Ozama as being stocked with arms and gunpowder in Glasgow before setting off for Haiti.
Dr Lee has so far recovered dinner plates and porthole windows from the ship, but hopes to discover more valuable items in the coming weeks.
He added: "The ship had a great history. It had been involved in smuggling guns to revolutionaries in the Caribbean and carrying large amounts of money.
"The steamer was once seized by Haiti, with the captain of a US warship threatening to shell Port-au-Prince if the steamer wasn't immediately released.
"I do plan on donating some of the artifacts to various museums."