Saw Noah's ship in the sea briefly (6)
I believe the answer is:
marked
'saw' is the definition.
The answer and definition can be both related to thinking as well as being past participle verbs.
Maybe there's a link between them I don't understand?
'noah's ship in the sea briefly' is the wordplay.
'noah's ship' becomes 'ark' (Noah's ark in the Bible).
'in the' is an insertion indicator.
'sea briefly' becomes 'med' (abbreviation of Mediterranean; 'briefly' suggests an abbreviation).
'ark' placed within 'med' is 'MARKED'.
Can you help me to learn more?
(Other definitions for marked that I've seen before include "showing flag maybe" , "Took good notice of - . . . . . . my words?" , "Pronounced" , "Easily noticeable" , "Read, corrected and awarded a grade" .)