I presume you have an Islander that is at least a couple years old. If that is the case, I have done two older aluminum boats by just cleaning the bottom and painting with fine results-no peeling paint etc. I still own one of the boats that I did paint way, again no issues.
So the answer is yes, you want to make sure you purchase paint that is for aluminum boats as mentioned in the post above. If your boat has one of the anodes on the transom, you want to make sure you do not paint over that anode.