Well, the event I remember sounds remarkably similar but occurred in the mid seventies during a disembarkation of 824 NAS SeaKings from HMS Ark Royal to RNAS Culdrose in Cornwall.
We lifted underslung wooden chacons packed with both personal and squadron gear.
One chacon spun violently en route to Looe Bar with the result that the double doors broke open and the entire contents were deposited into the sea just off the coast. We were returning from a visit to the USA and this particular chacon contained mainly personal kit.
For the next few days the shoreline was covered in bits of clothing and teddy bears bought as presents!
Needless to say, a lot of people lost their best uniforms and the squadron lost about 10X as much gear as could possibly fit in a chacon
