On point response and advice from
ScubaSteve and
CajunDiva, other's comments were also full of good general information.
AKR has a great
muck dive, follow SS's entry point advice. AKR has a 1st rate muck dive with a very unique Roatan environment that features good water exchange from the open Ocean. Right under the boat docks is all the further you might need to go. Muck diving ain't for everyone, it's an acquired taste. Always wear at least a Lycra coverup, as such sheltered environs are ripe for stinging critters. This presents a great night dive location, but of the very few done from AKR (via once a week boat option), there are not many guests who flop-in off the dock for this Muck-o-Rama Feast. Highly recommended, venture further into the basin towards the Key on a night dive. Always ask for advice from the AKR DM as to minor boat traffic and choice spots.
Nudibranch and similar odd stuff? See CD's comments above. These macro critters inhabit a niche environment of shallow flat healthy & florid coral reef, not sloping, not deep. You find this specific shape of reef presented on the Southern shore, look in 20' and shallower. I think there's been maybe 7 different varieties commonly encountered, some are not exactly Nudibranchs per-se, but I get all giggly when I see whatever they are. I have no clue what I'm seeing, but we've noted all sorts of odd color variants of some, maybe not scientifically remarkable, but unexpected colors. The most common (and easily missed) is the Lettuce Leaf, and at night Spanish Dancers (not a Nudi, but cool), are in the water column 40' and shallower.


Just so we all understand, we're getting excited about Slugs, but divers who are seeing macro level stuff are demonstrably weird. Look in the shallow rocks in 1' (off any walkway) for the Sea Hare. Staying at AKR (or any non-South dive op) will not offer this super shallow dive profile, a venture South to Mary's Place presents a 45' - 95' profile, and as the top of the reef at the 45' mooring, it's slim pickings for micro.
Since
Mary's Place inevitably comes up as a topic, I'll give you my impressions after having done it possibly 150+ times. Most of us, me too, see the geographic chasm, that's about it. We're pretty busy just diving. I dove this site many times when it was "closed", assisting in surveys with the "caretaker", Doc Radawski. I'll bet he has 1500 dives there. What he pointed out to this otherwise blithering idiot tourist diver was simply amazing.
Below is a "Sun Zoanthid" (no clue why I remember this name).
Hundreds of Mary's Place divers pass over it each day and never see it. It is just past "the underpass" where everybody is looking up and elsewhere. I took a shot of it and my little on-board flash made it retract. Got to stop and look, but by this time you usually have 12 other divers with their face masks on your flippers. Don't rush, spread out, go slow.
There is so much stuff hiding in plain sight at Mary's Place, I quickly switched from my standard air to nitrox for Radawski's lengthy survey dives. When I lead groups there, I use air, the standard tour thru the narrow chasm is a quick blip to 70, then 95, then a safe fast ascent to 45' along a vertical open wall. This is the the great moment to look off onto the deep blue for Sharks, we're pretty close here to the Cara-a-Cara Shark Rodeo dive site. Most Mary's Place tours are 45 minute total BTs, although some tarry under the boat if they have more air.
Lionfish? My anecdotal report, after 27hrs BT out of CocoView in May 2015 on the South shore, I saw 3 of them. CCV DMs believe something is eating the eggs or the juveniles, they're only seeing occasional adults. Nature seems to be finding it's equilibrium, even after the end of the world was noted on the internet.