Hi Simonp
I live in South wales and I'm very familiar with the "Cleddau" waters.
I used to launch from a place called Lawrenny Quay (on Google maps as Lawrenny Yacht Station) which has excellent facilities and a chandlers, good slip, (useable at low tide)however, the waters are brackish
(high rise and fall of tides with strong currents on the turn so be aware!)
There is a hose pipe flush out facility at the top of the slip..
also there is a hotel/pub that does excellent bar meals,
the Hotel is called the Lawrenny Arms Hotel, plus across the road there is a caravan site with touring pitches with hook up. I've got the contact no.'s so if you P.M me I will send them to you.
The Cleddau is an awesome location with 15 miles of waterway and no speed limits!
,so, down river towards Pembroke Dock / Neyland there are numerous pubs and restaurants where you can moor up etc .
.if you need more info please let me know.P.S Fuel also availiable at Lawrenny Quay but at silly prices as you can imagine but useful for emergencies !
Cheers
Welsh Healey