Every bit as practical as they were philosophical, Hellenic traders singled out the feature they found most attractive about Ibiza: its availability of shipbuilding materials. The ‘Ulyssian’ nature of ancient commerce made it imperative to have outposts, staged at regular intervals, where repairs could be made. Logically, any stopover which facilitated naval maintenance was viewed as desirable and visited frequently. Ibiza lent itself perfectly to this task and, in conjunction with other strengths, became one of the important nodes in the western Mediterranean network of connectivity – ultimately more Punic than Greek, but nonetheless a functional port of call for ships of all nations.
Not only was there timber for the taking, there was also the possibility of obtaining pitch, a thick sticky substance manufactured from the resinous sap of pine trees and used in sealing ships. The age-old method of repairing leaky hulls consisted of beaching and careening the vessels, plugging the cracks with hemp fibres and sealing the wound with pitch. If the damage was severe, rotten planks would be replaced by new ones and the fresh joints then sealed with hemp and pitch. An interesting fact is that not only was pitch one of antiquity’s only water-proof substances, but it became even more impermeable upon contact with sea water.
The full article is here: Traditions of Ibiza: Timber and Pitch tar