Disregarding odds, unties astern -- the US task, finding wartime havens (6,4)
I believe the answer is:
nissen huts
'wartime havens' is the definition.
(type of steel hut used during the world wars)
'disregarding odds unties astern the us task' is the wordplay.
'disregarding odds' indicates alternate letters (letters in odd-numbered positions are removed).
'unties'+'astern'+'the'+'us'+'task'='untiesasterntheustask'
The alternate letters of 'untiesasterntheustask' are 'NISSEN HUTS'.
'finding' is the link.
(Another definition for nissen huts that I've seen is " Prefabricated military buildings".)