Used to have a great uncle who lived there during the war. He never mentioned any crashes in the mill ponds (there are two) that I recall, just the high street getting machine gunned by a 'Bosche' hit and run raider sometime in the midwar period. There is a plaque on a railway bridge to commemorate the crew who died in a collision on the Hampshire/Sussex border - but from memory that is/was a meadow (or housing estate now, probably). Recall seeing mention of several Wellington incidents - almost certainly out of Thorney Island - in the first 5-10 years of the post war, but again nothing mentioning the mill ponds.
Wouldn't bother with the local newspaper if I were you - the (Portsmouth) Evening News then, The News now; I used to work there - and there is no indexing in any form (pictures or text) for the war years and no staff to do the searching for you (last I heard she was still on maternaty leave...). The Central Library, Portsmouth, might have the war years indexed and micro-filmed - but then you are reliant on the event not being judged as likely to affect the morale of the local population...
Let us know if you get any more information though - you never know!