There's absolutely no reason why you couldn't, so long as you have the necessary seamanship and navigation skills. However, it occurs to me that if you already have these skills, you wouldn't have to ask this question.
The Atlantic Ocean.
The Strait of Gibralter connects the Atlantic Ocean with the Mediterranean Sea.
The Strait of Gibraltar (36 miles long)
Through the Panama Canal.
To sail from Ireland to Italy, you would primarily navigate through the Irish Sea and then enter the Atlantic Ocean. After crossing the Atlantic, you would need to sail through the Strait of Gibraltar to enter the Mediterranean Sea, where you can finally reach Italy.
Ages you'd have to go down through Panama then cross the Atlantic then through the Gibraltar strait
Pacific ocean and Atlantic ocean
The Straits of Gibraltar connect the Mediterranean Sea with the Atlantic Ocean.
The Panama Canal ends at the Atlantic Ocean. :)
The Straits of Gibraltar.
The Panama Canal joins the Atlantic and Pacific Oceans.
In the Strait of Gibraltar