The section F-NS is divided into the following Model groups and classes:
 Group F2
true-to-original scale model ships built according to technical documentation without using commercially produced parts
Class F2-A
true-to-original scale models up to a length of 900 mm.
Class F2-B
true-to-original scale models up to and between the length of
900 and 1400 mm.
Class F2-C
 true-to-original scale models with a length over 1400 mm.
Group F4
models built from kits that are, or have been, available on the market  for at least one year or industrially produced parts, these models must have the general characteristics of a ship, and look as if they  are completely finished.
Class F4-A-
 models built from kits or industrially produced parts, that have the characteristics of a ship, also commercially built models (RTR Ready to Run, ARTR Almost ready to Run) these models just undergo a steering evaluation.
Class F4-B-          models that undergo a steering and construction evaluation.
Standard model kits.
Class F4-C-          models that undergo a steering and construction evaluation.
Injected Plastic model kits, that can be, with the use of other
materials, improved or changed. However, the hull, decks and superstructure must be from the kit contents.
Group F6/F7
Class F6/F7-
true-to-original and close-to-original scale models of ships and boats for team manoeuvres (F6) or individual manoeuvres (F7) as well as equipment, if in connection with the types of ship/boats (i.e., floating cranes, drilling rigs, dockyard machines/installations for transferring cargo, suction and bucket ladder dredges, etc.)
Group F-DS
Class F-DS
true-to-original and close-to-original scale steam-driven models, with propeller, side paddle or rear paddle wheels. It has to have a fully functional steam engine (of one or more cylinders) or steam turbines. An electrical drive unit for single cylinder and expansion machines to get over the dead point is allowed. The models in this class can either be “scratch build” or bought as a kit.
Group F-NSS
 true-to-original and close-to-original scale sailing boats in any scale. The true-to-original likeness of the model will be evaluated as part of the construction evaluation.
Class F-NSS-A
Fore-and-aft Bermudan rigged Ships (also flat top modern sails), wishbone gaff rig, without square sails.
Class F-NSS-B
Gaff and lugger rigged Ships (without square rigging).
Class F-NSS-C
Square rigged ships and other types of sails (e.g. Latin sails).
Class F-NSS-D
multi-hull boats and boats with special drives.