‘Already feel the monotony of life’, Sastri scrawled in his diary on 30 April 1919. The Arabian Sea was calm; the SS Manora travelled at a leisurely pace of about 12 knots per hour on its journey towards England. This was his first trip abroad. On earlier occasions he had pointedly refused to go overseas because of his mother's illness. Now when he had grudgingly given in, Balambal fell ill and never recovered. She passed away soon after he arrived in England.

Anxiety about his mother's health and recurring bouts of back pain chained him to his cabin for long periods on the ship; the motionlessness of time snoozing in sync with his body. The cabin that he shared with three other people had a porthole and a fan, making it barely tolerable. The proverbial silver lining was that he spent his days feasting on books and writing letters to family and friends. Of all of the ship's passengers from Bombay only nine were Indians. Six of them were Indian political leaders travelling to London to present evidence on the historic Montagu–Chelmsford Reforms. Sastri and H.N. Kunzru, both from the Servants of India Society, were representing the moderates. Kunzru, younger than Sastri by 17 years, was the more experienced traveller of the two, having studied at the London School of Economics. In views as in temperament, Sastri and Kunzru were quite alike.

The other four politicians were going to join the veteran radical Bal Gangadhar Tilak to represent the Congress’ point of view; although it was not clear if Tilak, who was in London to fight a defamation case against the journalist Valentine Chirol, would be the leader of this delegation. Vithalbhai Patel, a firebrand lawyer and member of the Indian Legislative Council, had recently introduced a bill to legalize inter-caste Hindu marriages, for which he faced the scorching ire of Tilak's papers, Mahratta and Kesari, ostensibly for the crime of polluting Hindu culture. With no love lost between the two, Patel, now on his way to London, was clear that Tilak could not be the delegation leader.