Answer: The Greeks were expert shipbuilders, and their techniques are still used today.
The topography of Greece was very mountainous, having rocky islands and and all the places there were pretty close to the sea. For this reason, the ancient Greeks had to use the boats to travel from one place to the other, specially for the purpose of trade with the rest of the world.
Their need to use boats this often led them to become expert shipbuilders and their techniques are still followed in this era.