You will have to look in the MSgames/data/ships.ini file to find the ship that is yours and make a change. Sample below
Ship
ids_name = 237035
ids_info = 66573
ids_info1 = 66574
ids_info2 = 66608
ids_info3 = 66575
ship_class = 2
nickname = li_freighter
LODranges = 0, 80, 120, 200, 300, 1200
msg_id_prefix = gcs_refer_shiparch_Libf
mission_property = can_use_large_moors ; change to this can_use_berths
type = FREIGHTER
DA_archetype = ships\liberty\li_freighter\li_freighter.cmp
material_library = ships\liberty\li_playerships.mat
material_library = fx\envmapbasic.mat
envmap_material = envmapbasic
cockpit = cockpits\liberty\l_freighter.ini
pilot_mesh = generic_pilot
nanobot_limit = 12
shield_battery_limit = 12
mass = 300.000000
linear_drag = 1.000000
hold_size = 80
fuse = intermed_damage_smallship01, 0.000000, 400
fuse = intermed_damage_smallship02, 0.000000, 200
fuse = intermed_damage_smallship03, 0.000000, 100
max_bank_angle = 15
camera_offset = 8, 45
camera_angular_acceleration = 0.035000
camera_horizontal_turn_angle = 20
camera_vertical_turn_up_angle = 5
camera_vertical_turn_down_angle = 20
camera_turn_look_ahead_slerp_amount = 1.000000
hit_pts = 1600
If your not into modding the info, remeber, not all moors are for large ships.