https://www.marinetraffic.com has most AIS transponders, I use it to track friends on commercial and private vessels.

https://aisvesseltracker.com/ is a good one too. Shows a LOT more, including cruise ships and pleasure craft.

It's also a bit limited. The gold standard is still kpler.

Thanks for the recommendation, looks interesting. I've used Vessel Finder due to something being a nuisance with Marine Traffic.

https://www.vesselfinder.com/