What is "Shesh b'Rikmah"?
Rashi: It is a linen garment with embroidered designs.
Radak: They are embroidered linen curtains from Egypt; linen Kelim come from there. In Tzor, they did so for grandeur.
What are "Mefarshech"?
Rashi: They are sails.
What is "Nes"?
Rashi: It is a flag, to spread on a cedar beam and raise it on the mast.
Radak: It is the curtain that they spread on the mast. This is like "Bal Yechazeku Chen Tarnam Bal Paresu Nes" (Yeshayah 33:23)
What do "Techeles" and "Argaman" refer to?
Radak: They are garments dyed with these colors, for beauty, brought from the islands of Elishah.
Where are the islands of Elishah?
Radak citing Targum Yonasan: The land of Italy.
What is the purpose of "Mechasech"?
Rashi: It is a tent and roof over the entire boat. Radak #2 - it covers people from waves that splash onto the boat, rain and scorching heat [of the sun].
Radak #1: They are your clothing.