The concern over tubbing is about whether the product can be readily available for inspection. That's the concern. There's no concern about freezing prawns in sea-water, other than you can't see them to see if they're meeting the size limits. If you can find a methodology to assess size limits, then the issue is resolved. That's what the protocol does. It sets out a protocol to allow for a ready inspection to ensure that size limits are being respected.
On May 26th, 2021. See this statement in context.