"The ships of Tarshish serve as carriers for your wares. You are filled with heavy cargo as you sail the sea."
NIV
The ships of Tarshish were your caravans for your merchandise, and you were replenished [Tyre] and were heavily loaded and made an imposing fleet [in your location] in the heart of the seas.
AMP
The ships of Tarshish did sing of thee in thy market: and thou wast replenished, and made very glorious in the midst of the seas.
KJV