Since the Wonder is a foreign-flagged vessel, it cannot do one way cruises from California to Hawaii. It's prohibited by the Passenger Services Act. If they do cruise to Hawaii, it would have to be round trip. Passengers would not be able to jump ship in HI either.
The ship would have to make a foreign port stop to do one-way cruises, or begin or end in a foreign port - such as Vancouver or Ensenada.
Here's an example of a one-way cruise on Carnival Spirit from Honolulu to Ensenada:
Sunday, Sep 26 Honolulu, HI 1:00pm
Monday, Sep 27 Honolulu, HI 6:00pm
Tuesday, Sep 28 Kauai (Nawiliwili), HI 8:00am 6:00pm
Wednesday, Sep 29 Kona, HI 8:00am 6:00pm
Thursday, Sep 30 Hilo, HI 8:00am 6:00pm
Friday, Oct 01 Maui (Kahului), HI 8:00am
Saturday, Oct 02 Maui (Kahului), HI 6:00pm
Sunday, Oct 03 Fun Day AT Sea
Monday, Oct 04 Fun Day AT Sea
Tuesday, Oct 05 Fun Day AT Sea
Wednesday, Oct 06 Fun Day AT Sea
Thursday, Oct 07 Fun Day AT Sea
Friday, Oct 08 Ensenada, Mexico 8:00am
Here's a repositioning cruise from Honolulu to Vancouver before the start of Alaska cruise season:
Fri Apr 23 HONOLULU, HI 13:00 PM -
Sat Apr 24 HONOLULU, HI - 18:00 PM
Sun Apr 25 KAUAI (NAWILIWILI), HI 08:00 AM 18:00 PM
Mon Apr 26 KONA, HI 08:00 AM 18:00 PM
Tue Apr 27 HILO, HI 08:00 AM 18:00 PM
Wed Apr 28 MAUI (KAHULUI), HI 08:00 AM -
Thu Apr 29 MAUI (KAHULUI), HI - 18:00 PM
8 FUN DAY AT SEA - -
9 FUN DAY AT SEA - -
10 FUN DAY AT SEA - -
11 FUN DAY AT SEA - -
12 FUN DAY AT SEA - -
Wed May 05 VANCOUVER, BC, CANADA 08:00 AM