Learn English – ny relation between the suffix “-ship” and actual ships

-ship is added to a noun to establish status or condition.

1. Indicating a state or a condition, e.g. to be in a friendship.
2. Indicating the qualities belonging to a class of people, e.g. craftsmanship.
3. Indicating office or profession, e.g. ambassadorship.

Quote from http://www.randomhouse.com/wotd/index.pperl?date=19990225:

The suffix -ship has been studied in some detail, but most of that detail is irrelevant to all but the most hardcore etymologist. The most important thing, in terms of its origin, is that it is unrelated to the word ship meaning 'a vessel, especially a large seagoing vessel'.

-ship is a suffix used to form nouns of state or condition, chiefly added to nouns and especially personal nouns. In Old English it was widely used with adjectives and participles, but only two of these survive (hardship and worship, from an adjective meaning 'worthy').

The uses can be divided into ever-finer distinctions, but there are some basic categories. It can denote 'quality; condition' (kinship; friendship 'the condition of being a relative/friend'). It can denote 'skill; act; power' (scholarship 'the acts of a scholar'; horsemanship 'the skill of a horseman'). It can denote 'number' (readership; listenership 'number of readers/listeners'). It can denote 'profession; office; position' (professorship 'the profession of a professor'). It can denote rank or title (ladyship; lordship).

The suffix was common in Old English, and is ultimately a form of the ancestor of the Modern English verb shape, in the sense 'to create; form'. Cognate suffixes are found in many Germanic languages; a form occasionally encountered is the German Wissenschaft 'science', from Wissen 'knowledge' and -schaft '-ship'.