You might have already gone but if not this will help.
I lived in Mallorca over 20 years and took a number of criuses from there. Your best bet is to get a taxi to the ship; BUT the ship is in the Junta del Porto zone and depending on who is on the gate and what mood he or she is in will decide if you can get a taxi directly to the embarcation building or not.
If they won't let you in you will have to go around to the ferry terminal go upstairs (there is a lift) through security who will want to see your boarding documents. It is then a long walk with your luggage (no trollies) to the embarcation terminal where you will then need to go downstairs to check in. After that it is simple!
It's very simple, having made sure you have your cabin labels on the main luggage and your tickets and passport to hand enter the "Embarkation Hall and you will be guided through every step of the way from there. Your information package will tell you what time to arrive but if I were you I would arrive earlier than that as you can normally board sooner than they say. ....Neil.
Thanks for that Neil, feel a bit more reassured now.