Margaret Field had taken a class of 31 pupils from Freemantle CofE infants, Southampton, with eight adults to Brownsea Island in June 2005. A few days before the trip, Mrs Field agreed an itinerary and full risk assessment with Wendy Hill, a visits co-ordinator.
Stephen Murfitt, presenting officer, told a General Teaching Council hearing: "On the day, Margaret Field changed the itinerary. Lunch was not held at the education centre but close to a steep incline where there were no borders or markers. She also allowed the children on to the beach when it had been agreed that this would not be permitted. To access the beach the children used steps that were potentially dangerous and which had not been risk assessed."
Following staff concerns, an investigation was held by Kevin Barrett, her headteacher, leading to Mrs Field's resignation in October 2005.
Giving evidence, Mrs Field, who recently began working at another school, cited lack of training for her "error of judgment".
Gloria Hyatt, chair of the committee, said: "Following training, Mrs Field now shows insight into her failings in June 2005. It was an isolated incident which was not deliberate. She has shown remorse, has a previous good history, and there is no suggestion that that there has been a repetition of such behaviour."
Mrs Field was issued with a reprimand which will remain on the register for two years. No children were injured on the trip.