West Wittering beach near Chichester reopened to visitors on Wednesday, with strict social distancing measures in place.
Tickets have sold out for its first three days of operation since it was closed to visitors on the 21st March, just before the lockdown began.
Security guards are in place to monitor the number of people arriving.
The owners of the beach say limiting the number of people who can park is "the only way to control numbers and ensure social distancing".
We feel that it's the only way to control numbers to ensure social distancing on the beach. Anyone that's been here before will know that we can have up to 20,000 people on our beach. If that were the case social distancing would be almost impossible. So we've made the decision to greatly reduce the number of cars we allow into the car park to ensure social distancing is met."
Normally, 20,000 people can use the beach at any one time, but that would make the two-metre rule impossible to enforce.
The public is being asked not to make the trip if they have not got a ticket as there is no parking in the local village.
The owners say it is "important to protect the local community".
People are being reminded that there is no lifeguard service at the beach, following delays in recruitment and training because of the lockdown.
The owners say that lifeguard teams will be in place from Saturday 30th May.
In the open letter, Mark Dowie said the easing of lockdown restrictions has put the charity in an "impossible situation".
He has requested the government restricts "access to the coast until we have lifeguard patrols back on beaches".
Things like the recruitment, the training, the induction of lifeguards themselves was just almost impossible under lockdown conditions. We're in a position to roll out a sparse service to maybe 30% of our usual total, so that's maybe 70 beaches across the UK."