Their arms depict a dark green sea turtle on pale green.
The current Lord of House Estermont is Lord Beric.
Ser Duncan the Tall spotted the Estermont turtle among the heraldry present at the tourney at Ashford Meadow. Ser Gunthor Estermont rode in the lists.
Robert Baratheon once spent a fortnight on Estermont with his mother's family. There he bedded a widowed cousin he used to play with as a child.
Old Lord Estermont was one of the insulting matches Prince Doran Martell proposed to his daughter Princess Arianne.