Fathom has reduced prices on its cruises to the Dominican Republic to less than half what they were listed at six months ago.
The line's latest price structure drops the lead-in rate to $499 for the weeklong cruise on inside cabins, including during peak season.
Previously, the least-expensive Fathom cabin was $974 during September, a hurricane-prone month in the Caribbean.
Unlike most cruises, Fathom's trips only go to Carnival Corp.'s private destination at Amber Cove, where the ship docks for three days while passengers participate in social-impact projects.
Fathom president Tara Russell said the new concept can be hard for some travelers to grasp.
"We are offering inaugural year pricing because we feel it is appropriate to expose our agents and other partners to this unique experience since it is a high-touch product," Russell said. "Agents who have participated so far have returned with tremendous feedback and are consistently selling or building awareness of the product."
Fathom's latest price structure drops the rates on other accommodations to $599 for an outside cabin, $699 for a balcony stateroom and $2,499 for a suite.
The prices apply to the balance of Fathom's inaugural season Dominican sailings running through Nov. 20.
This includes sailings in June, July and August, which were considered peak months under the pricing plan announced in October. At that time, inside cabins on the 704-passenger ship were priced at $1,465 per person, with suites listed at $4,468. Somewhat lower rates were listed for low and shoulder season cruises.
Some observers have speculated that Fathom's Dominican itineraries are not selling as well as its other product, a weeklong Miami-to-Cuba cruise that doesn't include volunteer work projects.
The lead-in price for Fathom's Cuba cruises, which includes a stop in Havana and two other ports, remains at $1,800, marking a wide gap between two itineraries on the same ship.
Russell said the demand has been higher for Cuba because it has been off-limits to American cruise passengers for so long.
"Cuba is an entirely different market and experience, and the pent-up demand and hunger for Cuba is significant," Russell said. "Fathom is fortunate to be the first to sail to Cuba in more than 50 years, and there is a large and growing audience eager to travel with ease, unpack once and see more of the enchanting island of Cuba."
Fathom's new pricing doesn't apply to its recently announced second season of cruises, which begins with a Cuba cruise on Nov. 27 and one to the Dominican Republic on Dec. 4.
Lead-in pricing for Dominican cruises reverts to $974 for the second season, which runs though December 2017.
"Prices for Fathom's D.R. trips in 2017 will be higher to better reflect the unique value of this experience, which is unlike anything else in the marketplace," Russell said.
Separately, the least expensive pricing for Cuba cruises from December 2016 to December 2017 was bumped up to $1,899.
In some cases, Fathom's new inaugural season prices put it below a comparable cruise from Miami on its larger cousin, Carnival Cruise Line. A seven-day cruise on the Carnival Glory departing Miami on Sept. 3, for example, is listed at $519 for an inside cabin.
But in other cases, similar Carnival voyages are less expensive by anywhere from $10 to $80 per person.
Russell said Fathom is a completely different product with a shorter history than Carnival, which has been sailing since 1972.
"Fathom is pioneering a new category of travel, social impact travel, in the D.R., and we are building brand awareness around travel with purpose," she said.