The answer is a bit convoluted. It goes way beyond log book entries for a dive vacation.
Times of the year are critical.
@scubadada , no surprise about August viz. it simply does not rain very much.
@Yakman58 , no shock that November sucked, it is statistically the rainiest month. Period. By February, it starts to slack off. Rain = Run off, creating cloudy viz.
On the North side, the siltation is carried West fairly quickly by a mild East>West current. TBR as mentioned above, lies at the Eastern end of Roatan’s present state of land development, so there’s not much siltation being crated. “upstream” of the proper5ty. The further West you go from there (AKR, WestBay, West End,etc), the siltation is punished that way by the mild pevailing current. TBR clears pretty fast, but downstream can linger.
Siltation by its very nature is found close to shore. All diving on the North side is a minimum of a 1/2 mile boat ride offshore. You simply are not diving in the worst of it. You are also diving deeper reefs that are sloping and are not specially florid with corals. Bigger apex fish are still localized, but they avoid hunting (and scatter) when colder brackish rainwater becomes the top layer of the ocean.
The OP dove CCV, and that is on the South side. The vertical walls are immediately just offshore, they start real shallow, they are covered in soft corals that ‘grab’ siltation, there is no real current. Whatever run off there is? It can hang around. CCV’s main draw is the shore dive, that can present as “icky” after heavy rains…but there is a trick.
Ask the DM’s or Patty at Dockside Dive Center. Look a’sea from the shore dive. See that RED BOUY to the left? The best viz will abruptly begin there and be just fine to the East.
The standard easy shore dive of the Prince Albert wreck and DC3 will be murk city after a rain. Paddle EAST for about 3 minutes and be happy.
Best idea? Avoid the rainy season.
Better advice? Learn to ”play” the local environment and conditions.
Remember: As Roatan has broadened it‘s appeal as being ‘all things for all people’, due to development, money and Scuba Diving Magazione, it was first recognized as the sole last remaining Mecca for Micro/Macro. The fixated experts on this topic do not care about Viz. They also hover around CCV.
It’s a multi-faceted answer.
By the way, if you need ‘VIZ’, cross the Bay Islands off your list On the best of days.