  The spin 1/2 baryons are pictured as a composite system made out of a "core"
of three valence quarks (as in the simple quark model) surrounded by a "sea"
(of gluon and $q\bar{q}$ pairs) which is specified by its total quantum
numbers. We assume the sea is a SU(3) flavor octet with spin 0 or 1 but no
color. This model, considered earlier, is used to obtain simultaneous fits for
masses, magnetic moments and $G_A/G_V$ for semileptonic decays. These fits give
predictions for nucleon spin distributions in reasonable agreement with
experiment.
