Orlando Bloom -- Miranda Who??? Parties with Boatload o' Chicks Before Fight

If Orlando Bloom was worried about Miranda Kerr -- hours before fighting Justin Bieber -- he wasn't showing it because he had his hands full with multiple hot chicks.

Bloom was cruising around the island of Ibiza Tuesday on a speedboat, pumping his fists in the air, dancing with beautiful women ... and looking like he's shouting, "Turn Down for What!" Ultimate bachelor's life.

Looking at these pics, it was VERY GOOD to be Orlando yesterday. Last night? Not so much.

Shoulda stayed on the boat, Orlando.