The largest cost overrun attributed to dolphin mitigation was the thruster wall designed to prevent coastal erosion and sediment from infiltrating the nearby Dolphin Quest facility.

A part of the original design for the new pier, it has nevertheless resulted in millions of dollars of extra costs - and is still not complete.

The thruster wall a large steel curtain acts as a shield so when ships arrive and depart, the mud and sediment stirred up by their propellers will not have a detrimental environmental impact.

The design however, has changed at least "four times", according to contractors Correia Construction.

And six months after the first cruise ship of the season arrived, it is still not in place.

The extra costs are estimated to run to around $4 million, according to Government. Dennis Correia, company director, said work started on the thruster wall in March last year, but costs snowballed because "the design changed".

"Once they wanted it straight and now they want it curved, and with baffles," he told The Royal Gazette.

"It is only last month we have come up with a final design. The dock was originally built for the Voyager class and not the Genesis class, so we had to change gears. It got redesigned four times."

Genesis is the latest and biggest class of mega cruise ship.

When The Royal Gazette spoke to Mr. Correia about the project in May, he said two thruster walls 50 ft high and 238 ft in length were planned.

"We are to put them in place this summer specifically to protect the dolphins," he said at the time. "The reason they aren't in is we lost 80 days due to bad weather."

However, Mr. Correia has admitted the thruster wall was still not in place.

"We got the final design four weeks ago," he said. "Weather permitting it will be complete in another three to four months."

Mr. Correia said it was felt it was better to wait until the cruise ship season was over so work could progress unimpeded.

In March this year, Premier Dr. Ewart Brown said the Dockyard project had run over budget by some $6 million, $3.7 million of which was due to "dolphin mitigation".

Mr. Correia gave this newspaper a breakdown of that $3.7 million in May. The largest figure related to $2,254,166 in extra costs for the thruster wall.

His list stated: "The price for Thruster Wall was $4,098,484 and 55 percent ($2,254,166) was allocated to the dolphin mitigation and 45 percent ($1,844,317) was allocated to prevention of coastal erosion."

Parliamentary Answers on the dolphin mitigation costs by the Ministry of Tourism and Transport stated: "Correia Construction thruster wall: $4,029,481."

According to the boss of subcontractor Norwalk Marine International however, the steel for the thruster wall was costed in the original $39 million budget.

"Most of the steel material was included in the steel purchases originally in the estimate," said Louis (Skip) Gardella.

"But the design wasn't complete and on top of the incomplete design, it did grow and he (Mr. Correia) had to buy some more steel, pipe piles and sheathing." A letter from project engineers Entech Ltd. to the Ministry of Tourism and Transport, dated March 3, 2008, states the reasons for a 'Revised Thruster Wall Design and Costs'. "Over the last several months, Entech Ltd. and Correia Construction have been in discussions with the Pilot Warden and the Harbour Master regarding the requirements of the proposed thruster wall for the above noted project," the letter states.

"The purpose of the thruster wall is to help prevent coastal erosion and sediment transport towards the Maritime Museum and Dolphin Quest, which is caused by the cruise ship when departing the new pier.

"The original thruster wall was designed to handle the forces exerted by the Panamax class cruise ship, which would berth bow north only.

"Entech was advised by the Pilot Warden and Harbour Master to increase the strength of the thruster wall so that it could handle the Voyager class cruise ship (one step above the Panamax class).

"In addition, Entech was also advised to design the thruster walls such that the Voyager class could berth bow north or south."