The Merchant of Venice opens with Antonio reflecting on the reasons for his feelings of sadness which "wearies" him. Solanio and Salerio, his friends, go to great pains to explain how, were they in his position, they would fret and pour over maps worrying about the wherabouts and safe passage of their ships.
The "argosies with portly sail" refer to Antonio's ships with full sails being masterful in the oceans.
The conversation between the three men almost amounts to small talk but is crucial in establishing the problem that will face Antonio later when he cannot loan money to Bassanio so that Bassanio can pursue Portia beecause his ships are on the seas
tying up his available assets, and this will lead him to seek a loan from Shylock.
The "pound of flesh" that Shylock will demand will determine the outcome of The Merchant of Venice as justice, compassion and mercy will be tested to the limit.