Why do some landowners allow cave diving without express permission?

Some landowners allow cave diving without express permission primarily to bypass certain liabilities that come with granting access to their property. When express permission is granted, the landowner may be held responsible for any accidents or injuries that occur on their land. By not formally allowing access, they can distance themselves from potential legal claims, as they can argue that the individuals entering the property did so without their explicit consent and thus assume the risks involved. This creates a scenario where the landowner is not liable for incidents that occur in the cave system.

In contrast, the other options, while they may seem plausible, do not align as closely with the motivations of landowners who choose this type of arrangement. For example, enhancing community involvement or generating additional revenue might be secondary considerations but often do not outweigh concerns about liability. Maintaining strict control over access is also contradictory to the idea of allowing cave diving without express permission, as a lack of express permission would inherently mean less control.