American Marine was contracted to take the Carthaginian II out and sink it on Dec. 13, 2005.

LAHAINA — Five years ago, Atlantis Submarines fulfilled its plans to keep the Carthaginian II, a historic replica of a whaling brig, from being scuttled far out at sea.

Today, submarine tour guests are seeing the results of Atlantis’ project to transform an aging, rusted out vessel into an artificial reef.

“Thankfully, we were able to keep the Carthaginian here in Lahaina where she belongs, but she is now serving a greater purpose as an artificial reef for fish and other marine life to flourish,” said Jim Walsh, general manager of Atlantis Submarines Maui.

“It’s a fantastic story about the benefits of environmental sustainability that only gets better with each passing day.”

The 100-foot Carthaginian II was originally built as a steel-hulled, two-masted schooner. The ship was later converted to diesel power and served for decades as a mixed cargo freighter in the Baltic Sea.

Divers took this photo of the vessel in 2007.

Lahaina Restoration Foundation (LRF) in 1973 purchased the freighter in Denmark, motored it to Lahaina and converted it into a replica of a whaling supply vessel for use as a whaling museum at Lahaina Harbor.

With rust threatening to split the hull in two, LRF first approached Atlantis in 2003 about buying the ship and sinking it off Lahaina for use as an artificial reef.

During the next two years, Atlantis prepared the Carthaginian II by cleaning the vessel thoroughly, receiving all state and federal approvals, and hiring a team of consultants to plan and execute its sinking.

Under direction by the Coast Guard, the vessel’s bilges were scrubbed and cleaned, the engine was flushed, and fuel tanks and lines were cleaned.

The state Department of Land & Natural Resources’ Division of Aquatic Resources checked the Carthaginian II to ensure it was clean, it lacked entanglements for marine mammals and that the vessel was safe for divers.

These photos of the Carthaginian II were taken this year. “The difference between five years ago and today in the growth of marine life has been amazing, and it will only continue to improve,” said Jim Walsh, general manager of Atlantis Submarines Maui.

On Dec. 13, 2005, the steel-hulled Carthaginian II was carefully sunk a half-mile off of Lahaina between Puamana and Launiupoko Park on a sandy bottom in 95 feet of water.

Atlantis chose this location because it lacked coral reefs and marine life in the area.

The company soon incorporated the fascinating sight of the sunken Carthaginian II into its submarine tour.

Guests in the 48-seat, battery-powered submarine enjoyed seeing the ship up-close in its permanent resting place, and as time passed, fish and other marine life began to make the vessel their home.

Five years later, Atlantis reported that the Carthaginian II is a thriving artificial reef with an abundance of colorful fish.

These photos of the Carthaginian II were taken this year. “The difference between five years ago and today in the growth of marine life has been amazing, and it will only continue to improve,” said Jim Walsh, general manager of Atlantis Submarines Maui.

The vessel’s surfaces are encrusted with plant and animal life — a garden tended by plankton-eating fish.

“It’s inspiring to know the Carthaginian has made such a profound impact on the area’s ecosystem,” said Walsh.

LRF started its restoration of the Carthaginian II in 1974 by sandblasting the hull inside and out so it could be painted. The interior was rebuilt.

The rigging plan was researched in England, and the basic dimensions were from an 1870 brig. All masts, spars, yards and iron fittings were fabricated by hand by LRF.

Carthaginian II’s hull was not made to carry sailing rigs. Ballast was installed — 15 tons of steel and cement — to keep the vessel from tipping over.

Moisture seeped in between the concrete and hull, rusting the Lahaina Harbor attraction from the inside out.

Atlantis Submarines Maui offers six undersea tours daily, departing from Lahaina Harbor each hour from 9 a.m. to 2 p.m. For information, call 667-2224 or visit www.atlantissubmarines.com.