Here are some offbeat things to do in Andaman
Visit Barren island
Glimpse by elephant beach
Shop by Aberdeen bazaar
Trek for bird watching at Saddle peak
Spend a day in the presence of Mayabundet forest
Since you are visiting havelock here are some offbeat things to try
Stop by Neil’s cove
Try night scuba
If seaplane tour is available enroll for it
Laxmanpur beach has some sunset views to click
Guitar island is in the shape of guitar stop by it
Try snorkelling in kalapathar beach.
Sea plane tour is not available since covid times and I don't think they allow snorkeling or any water activities in kalapather as the beach is filled with stones. Apart from car...scooters are available At a very nominal price
Easy mode of transportation is by booking a local cab or using day sightseeing car facility in the hotel you reside in. Other than these there are buses within Havelock provided you know the stops. Best would be car.
Neil's cove, scuba , kayaking , also I will go for trek at elephant beach woth seawalk...these are are all on my list...sea plane I need to check as after covid I think they have stopped.
thanks for the tip of snorkeling at kalapather.