Maltese diving regulation

[Bob DBF]

Your Open Water (OW) certificate (from PADI?) enables you to dive up to 18 m, right?.

There is no depth restriction on PADI OW other than recreational limits. There is a recommendation that new divers limit their depth until they gain experience. I don't know if Malta restricts depth according to certification, like some dive ops do, but nothing in the link provides that information.

 

[JustSurfaceInterval]

The sentence in the link is

Under Maltese regulations, divers are only permitted to dive independently if they have a diving certification that allows them to dive to a depth of 30m, otherwise they must be accompanied by a licensed instructor.

And PADI says:

PADI Open Water Diver [...] allows you to [...] dive on your own with a buddy (who can be another Open Water Diver and does NOT have to be a diving professional) up to a maximum depth of 18 meters/60 feet.

That's why @Mario007 who wanted to dive independently

discover that [PADI OW] is not enough to be able to rent out gear from a DS in Malta.

 

[Miyaru]

As said before, in Malta you have to be certified to dive to 30m, if you want to dive independently.
And because of the latest developments in Malta, don't dive with a Maltese buddy. If anything happens, Malta will prosecute in absurd ways.

In the Maldives, all diving is restricted to 30m max, including deep specialty courses and technical diving.
In Croatia, a very expensive license is required to go diving independently.
In Greece, solo diving and independent night diving is forbidden.
In Egypt, several dive sites are not accessible without a licensed guide.

Look into the diving related laws of the country you plan to visit. If you don't like it, pick a different destination.