Finished! Too early as well! Admittedly, I cheated slightly by taking a ferry across San Juan Harbour but given that meant I avoid a lot of traffic and industrial areas, I think I am justified! I came across a cyclist who had read about me just before I left Route 3 for Route 688. I am waiting for my hotel room to be ready in a plaza nearby.
Fidel Ramirez later made a comment which I may have accidentally deleted. It read:
"Nice to heard that everything was ok .....the ferry you just mention is the " lancha de cataño " so famous in PR .
Hope you like[d] your ride around PR"