Gen 6:14 Make thee an ark of gopher wood; rooms shalt thou make in the ark, and shalt pitch it within and without with pitch.
What is Gopher wood? According the the Concordance, it is Cypress wood. A boat must be water resistant and free from rot, does Cypress wood meet the criteria? I went to a wood data base; wood-database .com for the answers. I chose the Mediterranean Cypress as the probable species. Here are the data for this wood.
Rot Resistance: Rated as durable; mixed resistance to insect attack.
Common Uses: Utility lumber, fence posts, musical instruments (flamenco guitars), furniture, boatbuilding, and turned objects.
Workability: Overall easy to work with hand and machine tools, though areas around knots can be problematic. Reportedly difficult to steam bend. Glues, stains, and finishes well.
If the Ark were as a box then the wood would work, but if it was to be bent, it would not be a good choice. In college woodworking class I had a project to make; a window seat. The original was to be of mahogany, but I chose to use Black Walnut. The wood required bending, so it was placed in a wood steamer, looking like a large water heater with a door. I tried to bend the wood into the shape needed for the project, but it repeatedly would break. So because the Mediterranean Cyprus could not be steam bent, it may still have been in some curved form, as often depicted. What does the Bible say about it's shape?
Gen 6:15 And this is the fashion which thou shalt make it of: The length of the ark shall be three hundred cubits, the breadth of it fifty cubits, and the height of it thirty cubits.
Gen 6:16 A window shalt thou make to the ark, and in a cubit shalt thou finish it above; and the door of the ark shalt thou set in the side thereof; with lower, second, and third stories shalt thou make it.
Sounds like it was in the shape of a box.
Comments: Mediterranean Cypress is a long-lived tree, with a lifespan over 1,000 years; one specimen in Iran is estimated to be roughly 4,000 years old.
The wood was caulked with tar. I could imagine that someday this ark may finally be found because of the durability of its structure.