This is, without doubt prohibited

That there are rules and customs that something may or must be, so there are no regulations or even . So for the safe operation of the workshop prohibited: work with tools and machines that are defective.

Machinery and electrical tools and machines must be grounded. All electric machines must not be in direct contact with the water or near the water.  Quality of ground equipment or electrical outlets can test yourself.  Insulated wire with bare ends of the short circuit in the outlet line phase with earthed water. If the ground properly, GFCI breaker would currently be excluded from the power grid. WARNING! Do not do this if you're not sure what you want and if you have never worked with electricity.!

Never use a machine tool or if it is a part of the cable or peeled if you see bare wires. Unprotected contact with the wire can be mortally dangerous