Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE mission ( mission_id number, ship_id number, code text, launched_year number, location text, speed_knots number, fate text )
TABLE: CREATE TABLE ship ( ship_id number, name text, type text, nationality text, tonnage number )

### Question ###
Please show the most common type of ships.

### Accurate SQL ###

SELECT type FROM ship GROUP BY type ORDER BY COUNT(*) DESC LIMIT 1