Beautiful setting surrounded by snow-covered mountains and crags with many touring venues available a t dockside. The harbor island tour of cormorants, sea lions and the lighthouse provides great close-ups of birds and beasts plus spectacular views of the mountains.
The Otway penguin colony can be visited using group vans leaving from the main city square for a reasonable price. If your ship has to dock at the distant container port, group vans will take you and others to the main town square or back to the ship for $3/person. Take tours of the city and cemetery also.
The GVStein tour covering the main sights of PM and its surroundings can be arranged before you leave home. Just hope you have clear weather in frequently cloudy misty Puerto Montt to view the volcanoes.
Spend more time in Valparaiso and Vina del Mar than in Santiago. Christian the Van Man runs a good pick-up of disembarkees at the cruise ship terminal in Valparaiso. Ask for Andrea as guide and Louie as driver. Groups of 4 or 6 will cut your cost from the $125/person he charges for 2 people to tour from 8am-7pm airport drop off; HAL excursions charge $187/person in a large group setting. Eat lunch in Valparaiso ( Cafe Turri was great.)