Cozumel is often
deeper drift diving. And you typically either stay with the DM or risk surfacing in boat traffic. Neither is great for new divers with possible air/buoyancy issues. Unless you want to hire your own DM. There's also a little intimidation because some operators surface the group when the 1st people run low on air - more experienced divers sometimes can be a little harsh when that's you. Not right IMO but it is what it is - they also paid for their dive.
The BVI's might be an option also. One of our group had 10 dives and she did everything we did. DiveBVI's website:
New divers can take comfort from the sandy sea floor surrounding our islands which limits the vast majority of our dive sites to a maximum depth of 80 feet.
IMO that's optimistic - check the depths/requirements here:
Dive Sites | Dive BVI
It's nice diving, lots of fans, soft corals, low current. I don't remember any current in a week of dives except once. Many of the dive sites are sheltered by small nearby islands also. Even the Rhone wreck would be within your skill set later in the week - it's a pretty open wreck at 70' at the the bow - the rest of it is shallower. bviscuba.org lists all the operators in the area. We stayed on Virgin Gorda so used DiveBVI.
Parts of the BVI's can be a little pricey. Tortola is about the most reasonable. Virgin Gorda is more luxe resorts and vilas mostly. Although there are some reasonable small villa options on sites like vrbo.com. Leverick Bay resort was fairly reasonable but it's a little remote. If money is no object Little Dix Bay is stunning.
You could also do some dives of St. Thomas/St. John first also. Most people fly in there anyway - most movement within the VI's is by fast ferry - it's an hour or less from St. Thomas to Tortola. There's really shallow diving off the East End - one of the signature dives - Cow/Calf Rocks - can't be 40' deep anywhere. We did dives off Grass Cay that weren't much deeper. There's also wreck dives south off Charlotte Amalie - some as shallow as 30-40'. Blue Island Divers has an interactive map with details. And St. John is 1/2 hr. away - there's some good dives from there also. Even a car ferry so you can "drive" over.
Maybe consider Curacao also - it's all low current diving. We did a week of diving and only exceeded 80' twice to see something specific. Otherwise our dives were 40-60' along the reef. Since it parallels the shore navigation is pretty simple. The water is also amazingly clear - at some sites we saw the rope for the mooring ball a long way away. There's quite a few dive operators that cater to newer divers since they see a lot of cruise traffic also in town.
I consider it second only to Bonaire as the best
shore diving in the Caribbean. At certain locations it's better. The advantage Curacao has is most dive sites are accessed off the beach. On Bonaire most are dive docks over the ironshore or more likely crawling over it. Compare them here:
http://www.shorediving.com/Earth/ABC/index.htm
There's dive operators and food options at most Curacao dive sites - something Bonaire lacks once you leave town. Bonaire is worth the effort - just maybe not as new divers. Curacao is easier to get to - many Bonaire flights stop there first. In addition there's dive guides available for your initial shore dives - Bas Harts Diving, Relaxed Guided Dives or the Dive Bus are options among others.
Curacao Travel- Caribbean, Curacao, Dutch Caribbean lists it all.
From Portland have you considered Hawaii? There's easy diving off Maui. Molokini crater is the signature dive and usually calm - and shallow. Lots of fish and a chance to see smaller sharks also. Warm now also - I dive in a t-shirt there all summer til late fall.
And there's some easy shore dives also. Those can also be guided dives with operators like Shaka Divers or Maui Dreams Dive Co. Shore sites like Black Rock or Old Airport Beach near Lahaina don't exceed more than about 50'. Kapalua Bay/Beach to the north is one of the best beaches on Maui and the dive there is 40' or less. In south Maui there must be 1/2 dozen easy entry shore dives. Several good boat dive operators in either South or West Maui also. In West Maui, Lahaina Divers has the bigger boats and more of a mix of divers - 8 divers/DM is the rule there. In south Maui look at B&B Scuba or Mike Severns. The Severns crew are naturalists so it's more of an interesting ride.