Making Rubbermaid coolers for a living, I feel that I can speak to this subject. 298Vista is correct, the difference between the Marine and Ultra Marine is "Marine-grade extended life hinges"(may or may not be stainless), 'Vinyl coated stainless-steel lid strap", and"Reinforced non-slip, comfort grip swing up handles with tie-down feature" (sponge rubber on the handles and a hook to attach your bungee to). I don't think either have an insulated lid......
If you are set on Igloo, those are your choices....
If you want a replacement cooler that fits under your seat like the OEM Igloo that may have come with your boat, those are your choices.....
We make 102 and 150 qts with all stainless hardware and you can get them with refreeze bottles (3 in the lid and two as dividers) that help the prechill process and reduce the amount of ice needed

Some of the bigger coolers come with an insulated lid, Our Rubbermaid 45,50, 60, 75, 102 and 150 qt coolers come with an insulated lid. It helps to keep the drinks cold and ice from melting BUT, Ric hit the nail on the head when he talked about prechilling your cooler, it is a MUST for maximum staying power for your ice no matter what cooler you decide to buy......