Boat scene

The novel doesn't even mention Maurice taking a farewell gift when he goes to see Alec set sail - and Maurice decides to do this on impulse, making a premeditated gift unlikely:

‘When the Saturday came [Maurice] went down to Southampton to see the Normannia off. It was a fantastic decision, useless, undignified, risky, and he had not the least intention of going when he left home. But when he reached London the hunger that tormented him nightly came into the open and demanded its prey, he forgot everything except Alec's face and body, and took the only means of seeing them. He did no want to speak to his lover or to hear his voice or to touch him - all that part was over - only to recapture his image before it vanished for ever.’ (Chapter 45)

Earlier in the novel, however - straight after he's first had sex with Alec - Maurice (absurdly) thinks: 'He would have to give Alec some handsome present now, indeed he would like to, but what should it be? What could one give a man in that position? Not a motor-bike. Then he remembered that he was emigrating, which made the problem easier.'

This passage doesn't say what Maurice bought (if anything). A bigger problem is that Maurice's thinking on this is a symptom of his class unease - and if he'd gone through with giving this 'handsome present' (in effect, paying for sex that Alec had given freely: see his earlier refusal of the tip), I imagine Alec would have felt hugely insulted and the gift would have backfired.

One fan-fiction author (http://archiveofourown.org/works/39707) decided that the gift you see in the film was a very smart pen-set, bought with hopes that Alec would write to Maurice once he reached Argentina. From the shape/size of the package, I think it's more likely a bottle of whisky or similar. Mundane - but the kind of 'safe' gift Maurice would buy in a rush when he had little idea what was suitable.