They're more like sail assisted than really "sailing" as such. Worth doing in some cases but saves maybe 10% of fuel under optimal wind conditions. The most suitable vessels will tend to be bulkers, car carriers, and tankers. Container ships are actually the hardest to add sails because they interfere with the stacks and the port cranes.

10% is a lot though.

The Neoliner Origin is a pretty interesting ship. Perhaps more ships like it will start to show up as oil gets more expensive.

https://en.wikipedia.org/wiki/Neoliner_Origin

The Neoliner Origin is a joke. It's a marketing stunt to greenwash the importation of low-volume luxury goods like cosmetics for rich customers who want to tell their friends about how they're saving the planet. The design can't scale up to transport bulk cargo in a cost effective way.

Sure but you have to start somewhere. Ive been reading about https://en.wikipedia.org/wiki/Wind-assisted_propulsion for the last 30 years so I figure every slow step forward is still a step.

Gonna work great when ocean & wind currents die/change from climate change.