Almost the same. Cadets serve as Seaman Recruit (E-1) through Chief Petty Officer (E-7) rates. Senior and Master Chief Petty Officers are not used (don't think so anyway). Adult volunteers serve as Warrant Officers and commissioned officers (ensign through lieutenant commander only).
As for rank insignia, instead of straight stripes for Seaman Recruit through Seaman rates, chevrons are used (minus the Petty Officer's eagles). The Petty Officers' eagle/chevrons are the same as the US Navy's except they are a yellowish gold color.