A transatlantic crossing is never a quick cruise, but the Sea Cloud took its time going from the Cape Verde Islands to the Dominican Republic last year. That's because the ship sailed the 2,400-nautical-mile distance powered by 32,000 square feet of canvas for all but 100 miles of the trip.
The 17-day voyage was highly unusual. "Even for a tall ship like the Sea Cloud, sailing 96% of the time without engines, only with the help of the trade winds, is not typical for travel in the Atlantic Ocean," said ship captain Sergey Komakin.
But the voyage could be a back-to-the-future moment for cruising if the current concerns about climate change intensify.
Passenger shipping has evolved from a form of transportation during most of the 20th century into a purely leisure activity. Nobody needs to cruise in the way that they need to eat, or get to their job, or even fly to visit Aunt Sarah. The industry is certainly vulnerable to criticism as climate change activism increases.
The industry's response to climate change concerns has been threefold. First, and most effectively, it has reduced its output of greenhouse gases, such as carbon dioxide and methane, by becoming more fuel-efficient. The major cruise companies are on pace or ahead of their targets for slashing greenhouse gas emissions, but only because they've been strikingly successful at cutting per-passenger fuel consumption.
Secondly, the International Maritime Organization in 2018 set a goal of reducing the shipping industry's carbon dioxide output by half by 2050 and to be carbon-free by 2099. So that shows the regulators are thinking big. But much of the low-hanging fruit in energy savings has already been plucked. One industry executive said last year that cruise lines don't yet know how to practically meet the 2099 goal.
The third approach has been to launch a voluntary initiative to shift the fuel source primarily used for propulsion and energy generation at sea from petroleum to natural gas. And it has been neither easy nor cheap to change the shipboard fuel storage systems or the provisioning system to deliver liquified natural gas to cruise ports around the world.
Apart from global warming, burning natural gas is cheaper and produces almost none of the traditional exhaust pollutants, such as sulfur dioxide and carbon particulates, that have been identified as human health hazards.
But if it is an improvement on petroleum for those reasons, it isn't a huge improvement when it comes to greenhouse gases. The carbon dioxide content of natural gas emissions is about 30% lower than diesel fuel when adjusted for the higher energy content of natural gas relative to other fuels, according to the Energy Department. That's because natural gas is primarily comprised of methane, another greenhouse gas. Incomplete consumption and leakage of methane tends to offset much of the advantage that natural gas affords in lower carbon dioxide emissions.
The only type of propulsion in current use that doesn't produce greenhouse gasses is wind, but sailing ships are a tiny niche in the industry, with only Star Clippers, Sea Cloud Cruises and to some extent Windstar Cruises offering options.
Nevertheless, I wouldn't be surprised to see the segment grow in coming years, and for a large cruise company to start or buy a sail-powered line. If only for the optics, it would help fend off criticism if climate-awareness and activism continue to expand.