Why the city matters to the whole itinerary
Sri Vijaya Puram, widely known to travellers as Port Blair, is the main air gateway and an important ferry hub. Use city days strategically: they can absorb arrival/departure logistics, historical visits and the transfer needed before or after island sectors.
Do not squeeze a ferry and flight connection
Build a sensible buffer around air travel and island ferries. Exact transfer time depends on the confirmed sailing, reporting point, road conditions and airline schedule.
Use the information first. Book the right service second.
Compare packages, request current hotel or ferry rates, or add water activities only after the route and dates make sense.