Hello Jordi and Francesco,

We cannot be certain when ARGONAUTA was sunk. The destroyers DAINTY, DECOY, DEFENDER, ILEX and VOYAGER carried out depth charge attacks in the early hours of 29 June on three submarines for certain: TARANTINI, SALPA and UEBI SCEBELI and the latter was sunk (the attack in 35.24 N, 20.10 E actually occurred on 29 not 28 June). I have found no conclusive evidence that there was a fourth submarine and that it was sunk.
Although it is not impossible that ARGONAUTA was there, I have some doubts that she was sunk by these destroyers. SALPA and UEBI SCEBELI had sailed in company and TARANTINI had also sailed from Taranto a few hours later so it was not surprising that all three submarines were in the same area at that precise time but that a fourth coming from Tobruk would also be there, I find this to be quite a coincidence. I am inclined to classify ARGONAUTA as lost, cause unknown. One of these mysterious losses of the war.
The Sunderland's attack in 37.29 N, 19.51 E was on ANFITRITE and on 28 June (not 29 June). She was damaged and had to abort her patrol.

Best regards,

Platon