I will have to look at the Ecuador & Galapagos Guidebook again. I always viewed a Galapagos visit as primarily a dive trip with some land-based activities.
However, I can very much understand the perspective that it is a trip to 'The Galapagos' with some diving. There aren't many places like that - or they are categorized that way if the diving quality is only average.
Some places that might fit this category - to a lesser extent - include Hawaii, Thailand, and St. Lucia+Dominica for me, since there were Pitons/mountains to climb, sulfur pools to soak in, rivers to wade in, lots of waterfalls to see, black sand beaches, etc
Most Caribbean/FL locations are a bit uninspired outside of the beach and vibe.
I have sailed in the US Virgin Islands and the British Virgin Islands, where we typically dive the day before boarding the boat. However, since distances between the various islands are relatively small, dive outfits can bring equipment to you for the day if you are near a dive site —same with the Grenadines.
It appears that some sites in the central Galapagos Islands (as opposed to Darwin/Wolf) allow you to see 90% of everything:
Kicker Rock – San Cristobal
Kicker Rock is one of San Cristobal's standout dive sites. Rising around 150 metres out of the ocean, this volcanic tuff cone has divided in two, creating a thin underwater channel that reaches depths of 18 metres. Manta rays, spotted eagle rays, and frolicking sea lions can all be seen here, as well as whitetip reef sharks, hammerheads and the elusive Galapagos shark.
Gordon Rocks – Santa Cruz
Gordon Rocks is the remains of an eroded volcanic cone, and is undoubtedly among the best in the central islands. But it’s not for the faint-hearted. Washing-machine-like surge, ripping current, and impressive schools of hammerheads are the order of the day here, alongside Galapagos sharks, sea lions and fur seals.
Padi
If you're planning on diving in the Galapagos, be sure to add these 14 dive sites to your scuba diving bucket list.
blog.padi.com
I will be curious to hear your report.