We were on the Celebrity Zenith. The tours in Chile were not fed by the ship, however tours in Argentina were fed by the ship. In both cases the food was really poor in quality.
Can you imagine an unopened can of tuna and a cup of cold frozen mixed vegetables. (Birdseye's finest if you get my drift.) Another delacacy was fruit cake crumbs in a sandwich bag with the worst sandwich ever created by mankind on cheap white bread with the crusts removed. (They wouldn't want this sandwich to have any flavor.)
The Magdelena Island tour is in Punta Arenas, Chile. Punto Tombo is supposed to have more penguins but we did not find that so. Magdalena Island had far more and the island was a much more aesthetic setting in which to see them interacting, swimming, nesting, etc. There are also colonies of cormerants and Gulls on this island too.
If you choose Punto Tombo, the highlight of the six hours of the bus rides to and fro is one very average telephone pole which we photographed ten times just to get the lighting right. You probably think I'm joking but this was the longest, most boring bus ride of my 54 year life. We were not allowed to use the toilets on the bus either.