The canary islands were never under roman control, but they were close enough to roman Hispanic & Mauritania for control/settlement to be possible. What if the romans conquer the area and use it as a naval base of operations in the atlantic?
Could earlier contact with west africa be possible? Would the Azores be colonised earlier?
What happens to the canarian province after the empire falls (assuming that rome still falls ITL)? I imagine a sort of Roman pirate republic based there, growing immensly wealthy from trade and raiding in africa and western europe. What are your thoughts?