The President has conveyed his condolences to the grieving families of the deceased, a press release issued by Rashtrapati Bhavan said.
The President also called upon the authorities concerned to engage in speedy relief and rescue efforts and render all assistance to the kin of the victims, it said.
While 21 persons died, 29 were rescued and one person was stated to be missing in the boat tragedy that occurred yesterday in Andaman and Nicobar Islands.