Its looking mighty fine for the weekend for all water based activities, firstly the surf is looking goo all across the area including Llantwit Major closest to Cardiff, Southerndown, Porthcawl and Swansea. The tides are early morning, the wind is Easterly so mainly of shore, the swell is a ground swelll is a good interval between waves and a ride able size especially Saturday, the sun is shining and the waters still comfortable, so make an excuse and get in the water, there will always be time for Christmas shopping next year.
The rivers in the Brecon Beacons are flowing beautifully, the leaves are falling off the trees, the colours are amazing, this truly is the best time to be in the Waterfalls area either Gorge Walking or Canyoning. The river levels are perfect and the scenery to match so a day in the Gorge would be amazing.
Coasteering will all depend on the swell, the winds looking good and in the right direction, but the swell may be a little to high to be safe, also the tides are in the morning so this would be a morning to early afternoon event.
The conditions this weekend will be great for getting out and about, there's no better place in the world than South Wales at this time of year with these activities and these conditions.