Quark Expeditions says it will lower emissions by 86% by chartering in a cleaner expedition vessel newbuilding in an effort to cut its impact on the natural surroundings it showcases in its cruises to the Antarctic.

The Seattle-based company will charter a 167-berth World Explorer powered by four Rolls Royce diesel-powered electric generators for its 2018-2019 and 2019-2020 Antarctica seasons.

The Bergen engines are controlled by a Rolls Royce SAVe Cube integrated power management system that maximizes fuel efficiency and simplifies cooling.

The new engines and control system will limit emission of nitrogen oxide to within International Maritime Organization's Tier III, new-ship standard of 2 to 3.4 grams per kilowatt-hour of electricity.

Tier II protocol for existing ships allows up to 14.4 grams per kilowatt-hour for ships on the water.

"Quark Expeditions is committed to staying ahead of the regulations by taking a leading role in industry groups such as IAATO (International Association of Antarctica Tour Operators) to set a high standard for responsible and sustainable tourism in the polar regions," Quark Expeditions said.

The unit centralises distribution of electricity to the propellers and rest of the ship from a switchboard enclosed in a single cabinet designed to save space, the company said.

"Engine speed will automatically be adjusted to the power being demanded in the most fuel-efficient way," the company said.

In addition, battery power can be added to the unit for slow-speed transits in harbour or for peak power load smoothing, but the company said battery power will not be included at this time.

Quark declined to say whether its current or future ships will have the cleaner burning engines.

The ship, which will provide five 11-day cruises from January through mid-March of 2019 and 2020, is being built by Portugal's WestSea Viana Shipyard for owner Mystic Cruises.

Quark Expeditions, founded in 1991, charters nine vessels that carry under 200 passengers, including six expedition ships, two ice breakers and a 12-passenger exploration boat.