Masses of water wrecked canoes (6)
I believe the answer is:
oceans
'masses of water' is the definition.
'oceans' can be an answer for 'masses' (ocean can mean a mass or large amount of something). I'm not certain of the 'of water' bit.
'wrecked canoes' is the wordplay.
'wrecked' is an anagram indicator.
'canoes' with letters rearranged gives 'OCEANS'.
Can you help me to learn more?
(Other definitions for oceans that I've seen before include "expanses?" , "Large amounts (of water)" , "Southern Indian" , "Strange canoes on these waters" , "Large bodies of water" .)