Choose the next-day 4 day route if you want the calmest, cleanest expedition start after sleeping in Leticia first. Choose the same-day 4 day route if your flight lands early and you want full Amazon depth without losing arrival day in town.
Same route depth
Both versions are true 4 day Amazon itineraries with deeper river and community rhythm.
Main decision
The key difference is arrival logistics, not whether the route is complete.
Best next-day fit
Travelers who can reach Leticia the day before and start rested.
Best same-day fit
Travelers landing early enough to begin the expedition on arrival day.