  Supersymmetric models allow for stable non-topological solitons, Q-balls,
which can be produced in the early Universe and contribute to dark matter.
Experimental signature of electrically neutral Q-balls is, in fact, the same as
is expected for superheavy magnetic monopoles catalyzing baryon decay. Here we
use the upper limits on monopole flux obtained with deep underwater Cherenkov
array "Gyrlyanda" which operated in the Baikal lake in 1984-90 with 267 days of
live time to obtain the limit on Q-ball flux. The last has been found to be
equal to 3.9 x 10^{-16} cm^{-2} sr^{-1} s^{-1} (90% CL). This result is
discussed and compared with other restrictions.
