The most common and most likely answer to this crossword clue is the 4 letter word SAIL
S
A
I
L
More clues leading to the result SAIL
Buddy explains!

The straight part
We know that "Ships" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case ships = sail.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SAIL mean?
SAIL noun- A piece of fabric attached to a boat and arranged such that it causes the wind to drive the boat along. The sail may be attached to the boat via a combination of mast, spars and ropes.
- (nautical,uncountable) The concept of a sail or sails, as if a substance.
- The power harnessed by a sail or sails, or the use of this power for travel or transport.
- A trip in a boat, especially a sailboat.
- (plural "sail") A sailing vessel; a vessel of any kind; a craft.
- The blade of a windmill.
- A tower-like structure found on the dorsal (topside) surface of submarines.
- The floating organ of siphonophores, such as the Portuguese man-of-war.
- A sailfish.
- An outward projection of the spine, occurring in certain dinosaurs and synapsids
- Anything resembling a sail, such as a wing.
- To be impelled or driven forward by the action of wind upon sails, as a ship on water; to be impelled on a body of water by steam or other power.
- To move through or on the water; to swim, as a fish or a waterfowl.
- To ride in a boat, especially a sailboat.
- To set sail; to begin a voyage.
- To move briskly and gracefully through the air.
- To move briskly.