The route was north from Mactan to Malapascua, stopping to dive at Capitancillo Islet on the way there. Two morning dives at Monad Shoal, and although threshers came out to play only on the first one, the second dive yielded a a jellyfish that was probably a couple feet across. Aside from Monad Shoal, we dived Gato Island and Chocolate Island (total 10 dives in the Malapascua area over 3 days) then headed down to Pescador and Moalboal for four more dives, then to southern Negros - four dives at Zamboaguita, three dives at Apo Island, five dives at Dauin, and then started back north around east coast of Cebu. One dive at Oslob with the whale sharks, then three at Panglao, and on the last day, two dives at Cambaquiz before coming back to Mactan.
Marine life was biased toward macro, but there was plenty of wide-angle stuff as well, and my experience is probably colored by missing most of Dumaguete area and all of Apo Island due to having ear trouble for two days (I did 24 out of 32 dives as the result). I brought four lenses to use with my camera - 7.5mm fisheye, 10-18mm zoom, 16-50mm zoom and 90mm macro - and got to use all four of them. Lots of different shrimp and crabs, plenty of nudibranches, a variety of odd-shaped bottom dwellers, many frogfish, some small reef sharks, thresher sharks (only once, but still), whale sharks (in a soup of bikinifish at Oslob, but still awesome), schools of sardines and trevallys large enough to blot out the sun (seriously - at Napaling, Panglao, they said in the dive briefing that there might be a small school of sardines, then on the dive, it suddenly gets dark, and it's sardines everywhere), etc, etc. My album from the trip has ~300 photos; I will upload them once I get a proper connection.
Siren is by far the best liveaboard that I've been on, although my sample size is pretty small - MV Pawara in Thailand and VIP Shrouq is Egypt are my comparison points. It's very spacious - there is more room, per diver, than these other two put together. It carries fifteen crew and sixteen passengers in a space where they could have easily put in thirty plus divers and a few more guides. There are personal drawers at the gearing up stations and at camera work tables, the crew handle all the gear, literally a wall of power outlets to plug in all the chargers, two large rinse tanks just for the cameras and computers plus separate rinse tanks for wetsuits (where water is changed after every dive!) and masks. There is even free beer, which I don't partake in, but still find very impressive. Note that the liveaboard itself is too large to get near reefs, so all the diving is done from two Zodiac-type dinghies. Groups are 5-6 people + guide; most of the guides are local Filipinos. Entry is via backroll, and for exit they actually have a folding ladder on each dinghy - no acrobatics required. Fire extinguishers are everywhere, six out of eight cabins have escape hatches to main deck (two rear cabins are under the main saloon and there are couches where hatches would be), there is round-the-clock watch on the boat and drills are conducted at the beginning of every trip; there is even an oxygen kit on each dinghy, so they take safety very seriously. Dives are limited to 60 minutes, and I don't think we had any that lasted less than 55, with quite a few stretching to 5-10 minutes past the hour.
Gosh, sounds absolutely wonderful - thanks for the report, lucky you! Look forward to seeing your photos and wishing you a safe trip home!