halocline
Contributor
I am a big fan of Cocoview. No 100's, just 80s but after 5-6 dives a day you will find your happy zone and have no problem with hour plus dives.
One thing to remember with 100's and 120's. You are respirating that much more. Your nitrogen build up will be greater. Focus on slow and easy and the 80's will be fine.
If your main focus is bottom time cocoview cant be beat.
Going back for the 5th trip next week!
The OP asked specifically about the west end, so cocoview isn't for him. On a slight detour, I believe that the idea that you're breathing more gas with the bigger tank has no proven impact on N2 loading or DCS incidence. If that were the case, deco tables and computers would need to know how much gas you've gone through in order to calculate. Compartment loading and off-gassing is simply a matter of time, depth, and profile. But, if the bigger tank lets you stay down longer or go deeper, then, sure your N2 loading will be higher than would a shorter, shallower dive on a smaller tank.
I do agree with you that for most dives in Roatan you'd have to be a pretty big air hog to need a bigger tank. I think the OP will find that most divers will be using less gas on an average west end boat dive than on an average cozumel dive. The reefs are shallower, and the profiles are often very shallow for the last third of the dive. That's one of my favorite things about Roatan.
I'll add to the coconut tree recommendations. It's a terrific dive op and kind of a social hub for west end diving. You're going to have fun!