Multilayer golf ball containing at least three core layers, at least one intermediate barrier layer, and at least one cover layer

1. A multilayer golf ball comprising:

at least three core layers comprising a center, an inner core layer, and an outer core layer;

at least one cover layer; and

at least one vapor barrier layer intermediate between the outer core layer and the at least one cover layer and exhibiting a moisture vapor transmission rate less than that of the cover layer

wherein the center, the inner core layer, and the outer core layer exhibit a hardness gradient that decreases toward the moisture vapor barrier layer; and

wherein the center has a specific gravity that is within about 5% of a specific gravity of the inner core layer and a specific gravity of the outer core layer.

2. The multilayer golf ball of claim 1 , wherein:

the center hardness is no greater than about 60 Shore C;

the inner core hardness is less than about 60 Shore C;

the outer core hardness is less than about 50 Shore C; or

a combination thereof.

3. The multilayer golf ball of claim 1 , wherein the at least one cover layer comprises a thermoset or thermoplastic polyurethane or polyurea having a hardness from about 25 to about 65 Shore D and exhibiting a flexural modulus of at least about 2,000 psi.

4. The multilayer golf ball of claim 1 , which exhibits at least one of the following:

an Atti compression of less than about 110;

a coefficient of restitution of at least about 0.790;

a deflection under a load of about 100 kg of at least about 1.5 mm;

a cover surface having from about 250 to about 450 dimples;

or a combination thereof.

5. The multilayer golf ball of claim 1 , wherein the at least one cover layer comprises a thermoset or thermoplastic polyurethane or polyurea having a hardness from about 25 to about 65 Shore D and exhibiting a flexural modulus of at least about 2,000 psi.