SB3 is for breaststroke swimmers with co-ordination affected to a low degree in the upper-trunk and arms, with the rest of the trunk and legs highly affected, and those with a the absence of limbs.

These swimmers maintain good body position solely using their arms and upper body. Most will breathe alternately to keep their head low and bring their hips closer to the surface.

Swimmers must show intent to move symmetrically even if their arms and legs are not of even length.