Scuba-Bill:
My dive buddy had me book at Posada Arco Iris in the West End. We will see what we got ourselves in to...
It may be pretty 'still' over that way in July, so hoping that you have a nice fan or a/c would be a plus.
The stillness does encourage the little biting critters, so be cautious (do a search on this site) of insects like the famous sand fly. (no-see-um, sand flea, etc.)
Although Rooatan lies outside of the usual huricane path, you are there in the midst of the season. When weather arrives, it comes from the North and also shuts down the West end quite often.
If it does, be light footed and be ready to find a South side dive op, the best I have seen is Subway Water Sports located at the French Harbour Yacht Club- an excellent dive op.
The West End should be a-poppin what with vacationing young folk coming down and enjoying the best bargain in the Caribbean.
I have had great experiences while night diving in July August- the water column is filled with critters and the ocean is revving up to the August coral spawning. Things don't just happen at one time- there is a build up process.
In this time frame the best diving is on the full moon and the week thereafter.... in terms of sea life action.
Always take a magnifying glass to Roatan- and these months in particular. Go slowly, find a real hunter for a DM, see it all!