By Michelle Baran

Starting in 2015, American Cruise Lines will introduce four U.S. newbuilds over a period of less than four years, signaling that the company is confident the domestic small-ship cruising market is going to continue to grow for some time to come.

“I think there’s a greater awareness of it, and the market is growing,” said American Cruise Lines President Charles Robertson. “We have more demand than capacity.”

In order to meet that demand, American Cruise Lines plans on introducing a second paddlewheeler in early 2015. (Although the company hasn’t officially announced where the vessel will sail, Robertson said the Mississippi “would be a good guess.”)

The vessel, which will be a slightly larger sister ship to the 150-passenger Queen of the Mississippi the company launched last year, will accommodate about 154 passengers and will have certain distinctive features, such as higher ceilings than the Queen of the Mississippi. Like the Queen of the Mississippi, it is being built at the Chesapeake Shipbuilding yard in Salisbury, Md.

When the Queen of the Mississippi set sail in August 2012, it was the first paddlewheeler built in the U.S. since the American Queen (the 436-passenger paddlewheeler now owned by the company’s competitor American Queen Steamboat Co.) launched in 1995. But clearly, the steamboat style of cruise vessel is not an outdated mode for cruising.

Neither is cruising in the U.S. in general. According to Robertson, following the launch of the still-unnamed second paddlewheeler, the company will build three additional vessels that will be delivered about once every 11 months starting at the end of 2015. One will sail somewhere on the West Coast, one on the East Coast, and the location of the third is still undecided. Robertson said the new vessels will sail both coastal and inland waterways.

The Guilford, Conn.-based American Cruise Lines has experienced 25% passenger growth each year for the past three years, according to the company. It attributes that growth to strong consumer demand for the river cruising experience, its hundreds of travel agent partners, and the fact that the company is achieving some of its highest repeat booking rates in its history.

“The demand for riverboat vacations is higher than it has ever been,” Robertson stated in a release about the company’s planned growth.

American Cruise Lines operates more than 35 itineraries on rivers and waterways in 28 states.