Artist rendering of National Geographic Endurance

(11:50 a.m. EDT) -- Lindblad Expeditions' first polar new-build will be called National Geographic Endurance. The name was revealed during the keel laying of the ship at the CRIST shipyard in Gdynia, Poland.

The ship is named in honor of Ernest Shackleton's attempt to cross Antarctica from sea to sea via the pole, which ended when his ship, Endurance, became trapped in pack ice.

The occasion marked a major milestone in the construction of the Polar Class 5 ship, which is due for delivery in the first quarter of 2020.

"A Polar Class 5 rating gives us the ability to operate the ship freely at any time of year in polar environments vastly expanding our polar range, said Sven Lindblad, president and CEO of Lindblad Expeditions. "This means we can explore deeper into the pack ice, or further north to the unexplored reaches of the arctic. For instance, northern Ellesmere Island, where only a relative handful of people have ever been. Or some of the completely off-the-beaten-path arctic islands that are remote, pristine and teeming with wildlife."

As part of the keel laying, a newly minted commemorative silver coin etched with the name of the ship and flanked by a polar bear and penguin was welded into the steel. Lindblad also laid the lucky coin of iconic Lindblad naturalist, Tom Ritchie, a 1780 Austro-Hungarian thaler [silver dollar] with Marie Theresa on one side and a double-headed eagle on the other.

The 126-passenger vessel will feature an X-bow design, which provides fuel efficiency and smooth sailing; it will also have expanded fuel and water tanks to provide for extended operations in remote areas. Of the 69 cabins onboard, 75 percent will have balconies and 12 are designed for solo travelers. It will feature a spa and fitness area with treatment rooms, saunas, relaxation area and yoga room.

--By Dori Saltzman, Senior Editor