Port Olimpic harbor is located nearest to the sea. That means you get the most time at sea, instead of motoring in the harbor. Within 5 minutes you are at sea. Port Vell is located most central in Barcelona, so you may have a shorter walk to the boat location. It will take 15 minutes to get out of port Vell the sail boat and motor boat, because there are speed restrictions. The new harbor next to W-hotel is located farthest away from Barcelona's city center, with poor public transportation to the harbor. Only if you are staying in the W-hotel leaving from that port is sensible.