30 days of traveling around is good! it gives you a lot of flexibility. if you are not into wrecks that much i'd start by crossing coron off the list. on the other hand, if you ARE, put coron either at the beginning or end of your list. as mentioned, some of the wrecks are quite deep and nitrox certification is a must. if you are not already, get certified before you leave home. while you are there consider taking the time to visit el nido. not so much as a dive destination, but for the beauty of the area.
assuming wrecks are not at the top of your must-do list, leaving manila as soon as humanly possible, start out in the visayas. south leyte, malapascua, moalboal, dumaguete and alona are all within easy reach of cebu city. a possible itinerary would be cebu to tagbilaran, bohol (for alona) by ferry. stay at trudi's (or some other similar budget accommodation). tagbilaran to dumaguete by ferry. harold's mansion is frequently recommended. overland by public transport (including a short ferry crossing) to moalboal. stay at eve's kiosk and dive with nelson, next door. a long day by public transport will get you to malapascua, on the complete far side of cebu island from you. there are a number of budget choices on malapascua. consider an overnight or 2 in cebu city - a gem to some (including me) but a sh** hole to others - to break that journey up. there are dozens of budget opportunities in the fuente osmena area, from where all of your local transportation needs can be accomplished on foot or by jeepney. from malapascua return to cebu, overnight on mactan island, and fly to manila early in the am, so as to be able to get to the batangas ferry terminal in time to reach puerto galera on the same day via bus from pasay. the last ferry departs around 4 pm. so you want to be on one of the countless buses out of pasay by no later than 12 (and better 11 to be on the safe side). get your rescue certification in puerto galera. the instruction from rick at frontier scuba is quality, but there are others to chose from of course. and there are many comfortable budget rooms available in the area as well. or instead of finishing in, start in puerto galera, and then work your way clockwise or counterclockwise around the visayas. you get the idea.
a couple words about south leyte: the sogod bay area can be visited by an out and back ferry trip from cebu city. the ferry takes +/- 5 to 6 hours. it is a great, slow living area with some terrific diving, maybe some of the top diving in the philippines. peter's offers cheap rooms, as well as 400 peso dorm space. it is left off many itineraries because it does require a little more time/effort to get to. which is a shame. most people who visit the area rave about it. it is also possible to start your trip by going to south leyte from cebu, then taking the ferry to bohol from leyte, and overland south to alona. this is a long day in ferries and on buses, but it is easy to do and with 30 days, something i'd strongly consider. if running out of time, any one of these destinations can be sliced off your plan, with little serious effect on overall logistics.
a strong word of caution - half of philippines seems to be travelling somewhat before and after christmas. it is wise to plan ahead for this time especially. flights in and out of manila especially become a victim of a general and stunning incompetency on the part of cebu pacific in particular. be on the ground, preferably where you plan to be, in a room reserved well beforehand.
