Chain Speak. Is G3 The Same As Bbb

[Seafarer]

Found someone on Craigslist selling "300' of G3 chain used less than 1 year on large sailboat. $1/ft"

I offered him $250 for all and he accepted, but I need to know that this is the right chain to fit the gypsy on my windlass.

I was planning on saving up for HT stuff. However, the 3/8 BBB I'm using now has certainly served well enough that for 1/5 the price of HT I'm willing to go with more of the same!