Antique buying - shipwreck pottery

[AdviceAdvice123]

Big birthday coming up for my mum. I know she’s always wanted a piece of shipwreck pottery. I’ve never bought proper antiques before. How do I know what/who is genuine? Anything to look out for? Budget around £200!

generally with antiques from genuine sellers and even auctions there are rules regarding description
borrowed from an auction site
"
This is the conventional way of describing the relation between the artist and the work of art.
Pablo Picasso. The auction house believes this is an original work by the artist.
Pablo Picasso. Replica. The auction house believes that the artist him/herself made this work as a replica of their own, previous original.
Pablo Picasso. Attributed to. The auction house finds it likely that this is an original work, but is not prepared to guarantee this.
Pablo Picasso. His studio. The auction house believes that the work was made in the artist's studio and possibly under their supervision.
Pablo Picasso. His circle. The auction house believes that the work was made by another artist but during the lifetime of the named artist and in their manner.
Pablo Picasso. Follower of. The auction house believes that the work was done in the manner of the named artist, during their lifetime or later.
Pablo Picasso. In the manner of. The auction house believes that the work is done in the manner of the named artist but after their lifetime.
Pablo Picasso. After. The auction house believes that the work was made by another artist, based on an original work by the named artist.

you are looking for Provenance for shipwreck pottery such as recovered from wreck of XYZ ship in 1976 which sank in 1872
is better than recovered by wreck divers in 1990
some recoveries are authorised some are not, it depends if the wreck is actually owned and whether divers had permission to recover or just explore, bit like metal detecting, some have landowners permission others sneak onto sites under darkness to steal artefacts for profit
it depends on age ancient greek amphoras are not actually that rare, they are not 10 a penny but they are not worth £10,000's

@Cottagecheeseisnotcheese thank you, that gives me a good direction to research some more!

A tv shopping channel used to sell pieces from the shipwreck of the Tek something. Tel Sal or Sing perhaps?

The items were affordable. Have a google and see if there are still items for sale. Doubt the shopping channel is still selling them after all these years but others will be.