Q:

"Sneaked off" vs "sneaked into" vs "sneaked away."

I often get confused about which one to use. Example:

He sneaked [...] to the rear of the ship.

Or maybe all of them have a different connotation?

A:

Sneak denotes stealthy movement:

verb (past and past participle sneaked or informal , chiefly North
  American snuck)
1 [NO OBJECT, WITH ADVERBIAL OF DIRECTION] Move or go in a furtive or
  stealthy way:

Various directional adverbs can refine the sense of stealthy movement:

In He sneaked away to the rear of the ship, away suggests motion from the point of reference--a literal or metaphorical distance:

adverb
1.0 To or at a distance from a particular place or person:
she landed badly, and crawled away...
1.1 At a specified distance:
when he was ten or twelve feet away he stopped
1.2 At a specified future distance in time:
the wedding is only weeks away
1.3 Towards a lower level; downwards:
in front of them the land fell away to the river
1.4 Conceptually to one side, so as no longer to be the focus of attention:
the Museum has shifted its emphasis away from research towards exhibitions

In He sneaked off to the rear of the ship, off also suggests motion from the point of reference:

1.0 away from the place in question; to or at a distance:
the man ran off
1.1 Away from the main route:
turning off for Ripon
3.0 Starting a journey or race; leaving:
we’re off on holiday tomorrow

In He sneaked into the rear of the ship, into expresses motion to enclosure--literal or metaphorical:

preposition
1.0 Expressing movement or action with the result that someone or something becomes enclosed or surrounded by something else:
cover the bowl and put it into the fridge
2.0 Expressing movement or action with the result that someone or something makes physical contact with something else:
he crashed into a parked car
3.0 Indicating a route by which someone or something may arrive at a particular destination:
the narrow road which led down into the village

Oxford Dictionaries Online

