Any ships between countries in The Pacific

I love The Pacific and would love to explore more. I have two questions.

1. Is there any ships/boats between countries in The Pacific?

2. As airfares is expensive so I was wondering if there are any airpasses I can buy to go many destinations? Air Pacifics Bula Pass is no longer possible :(

Any help is highly appreciated.

The short answer is "no" to both questions.
While you can travel by boat within one country, there are no scheduled passenger ships between countries. The main options are cruise ships which usually visit more than one country, or crewing on a yacht.

I was wondering if there are any airpasses I can buy to go many destinations?

Star Alliance has a Micronesia pass that could be useful if you plan to visit that area.
They also have a South Pacific pass but you would need to backtrack to NZ to fly between two different Pacific countries.

"Passenger" (eg not cruise or cargo) boats between countries that still exist (ASFAIK):

PNG - Solomons
Vanuatu - New Caledonia
Fiji - Tuvalu - Kiribati
Samoa - American Samoa
French Polynesia - Pitcairn

The Samoa run is the only one that is fairly frequent, legal and economical.
The others are infrequent, expensive or even semi-illegal (PNG to Solomons).

And indeed, the Micronesia Pass of Star is the only one worth considering.
Within the South Pacific, just get the cheapest OW fares you can find to put together an itinerary.