I like the ocean; have been a passenger on ~ 35 ocean cruises. When referring to “bluer” ocean cruising, I mean better for the ocean; kinder to marine life. Let’s aim for constant improvement in these regards; here are some of my personal thoughts. Your own thinking & conclusions are also necessary. I like big cruise ships. Let’s look @ the new Icon of the Seas (“Icon“). Said to be the largest cruise ship operating now.
There aren’t many more-affordable alternate fuel/power ships yet; I’d prefer to travel on them whenever possible. Although in some areas of the World there are no LNG-powered ships cruising there yet. Going forward I will aim to give my business to those more affordable cruise lines where currently, all their new builds use LNG to power them around, and/or the new builds have the ability to switch to even more sustainable fuels when possible/available. So that means, for me currently: some of the cruise line brands within Carnival Corporation (incl. Carnival Cruise Line, Princess Cruises, Costa Cruises). It also means MSC Cruises, & now Royal Caribbean International (they just launched an LNG ship with their recent debut of Icon). I Would also like to sail on smaller (expensive) ship brands that are already more sustainable, but currently their higher cost can be a barrier for me.
General current estimates are that as a passenger on a newer more efficient ship, one might generate ~ 2x the amount of total greenhouse gases of a person who takes a short-haul flight & then stays in a hotel. Stat = per passenger, per kilometer. Per the cruise line: “with features like … LNG powered engines … & the ability to plug into electricity supplies at ports” they believe that Icon is Royal Caribbean’s “most sustainable ship to date”.
Icon: with stated passenger capacity of 7,514 plus 2,350 crew (can = almost 10k humans on board). Is said to be “one of many the same size or bigger that could be built in the next few years”. Is bigger less sustainable? Unknown by me yet. Any ship emissions on Icon can be divided by 10,000 (= how much emitted per person). How much emissions ea. on a ship with 10K people, compared to ? per person on ea. of 2 ships with 5000 humans? Haven’t seen that stat. General trend seems to be: newer/larger ships running more cleanly in some ways than older, smaller ones. Stats I looked up showed an equal no. of crew on Icon, as an aggregate of crews on two (3800-passenger) older ships. So no need to support more crew per passenger on the largest ship.
Some describe LNG as the “cleanest-burning marine fuel”. Yes & no… Less carbon dioxide emissions by a quarter, but an LNG ship may emit more greenhouse gas emissions overall. Burning LNG releases “less nitrous oxide, sulphur oxide & particulate pollution than traditional fuels”. But then: methane; via something called “methane slip” (of unburned gas). Currently, “nearly 80% of ships” burning LNG use engines that potentially leak up to “3.1 % of its fuel into the atmosphere”. Less leaky engines: are reportedly in the works.
Some think that all “ships should be using fuel cells & renewable hydrogen or methanol” to emit less greenhouse gases. There is quite a time lag between the design & the building of huge ships. Cruise line notes that when Icon was designed (> 7 years ago), LNG was then considered the “most promising fuel available at scale”.
Potential: “Icon was built to accommodate fuel cells” (= electricity w/o combustion) for powering its lifts, though such batteries had not yet been installed. Further, it was built for the cleaner alternative of running on electricity supplied from shore when docked. I read that only a few ports so far can supply ship electricity from shore.
& More on the plus (sustainable) side:
– the cruise line claims that it built Icon to be “adaptable to other fuel sources like methanol in the future”;
– same cruise line group is next year “preparing to debut Celebrity Xcel – a … ship with a tri-fuel engine …can also run on methanol”; &
– other innovation reported on Icon: “heat from the engines is used [repurposed] to warm water”.
Innovation challenges: time lag between design, & finished ship build. & Ships have a long life, so way(s) to convert older ships to more sustainable power would be a winning innovation. I’m looking forward to, has generally been stated: “newer ships with less leaky engines & more solutions are on the way”. I do think that progress is being made; let’s keep encouraging it.