Sea monster you know conceals a wrecked ark (6)
I believe the answer is:
kraken
'sea monster' is the definition.
'kraken' can be an answer for 'monster' (I've seen this before). I am not certain of the 'sea' bit.
'know conceals a wrecked ark' is the wordplay.
'know' becomes 'ken' (I've seen this in another clue).
'conceals' is an insertion indicator.
'a wrecked' indicates an anagram.
'ark' is an anagram of 'rak'.
'ken' going around 'rak' is 'KRAKEN'.
'you' is the link.
Can you help me to learn more?
(Other definitions for kraken that I've seen before include "Mythical sea monster (Norway)" , "Legendary monster of Norwegian seas" , "Sea monster that sleepeth (Tennyson)" , "A legendary sea monster of Norwegian myth" , "The -- Wakes (John Wyndham)" .)