Sadly the nearest public slipway is at
BeachleyProvision of slipways into the tidal Severn is woefull, there are a few private slipways but not so many. Theres a chap at Stonebench who has a slipway that can be used if you ask nicely and bung him a tenner but theres nowhere you can just pull up and launch over the bank without knowing someone. There's a slipway at Lydney, owned by Lydney yacht club. One of thier members has a hovercraft and launches from there, not sure how much membership would be.
I launch from my garden
at Minsterworth, SW of Gloucester, using a crane to drop craft over the bank into the river. The Severn can be an unforgiving place if you get the wrong time (the bore!), and some local knowledge is essential. Fortunately we have local knowledge! I occasionally have small "hover-ins" but I can only manage 2 guest craft at a time for various reasons, which is a bit limiting.
What sort of craft have you got?
Ian