You can go and do a websearch on yahoo for "health insurance providers". It will pop up one or more....and one of them will be Blue Cross/Blue Shield... go to that site and it will ask you to plug in information.... mostly generic, ie: age, if you smoke, and maybe something else....it will then give you the different plans available and the prices of the plans. Don''t be surprised if you can purchase a significant insurance plan for less than your COBRA fees.
As far as cruising ..... Blue Cross/Blue Shield has a site that gives information regarding which hospitals outside the country are participating with BC/BS Health Insurance. You should be able to access that site through BC/BS''s main site. There are many hospitals and I presume doctors as well all over the carribean.