The answer is simple but the solution - how to get to Subic Bay from Manila - is not quite so simple.
First off there are two air conditioned tourist bus services that travel from Manila to Angeles City every day - at the Swagman Hotel in Ermita, Manila City, and at the Southern Cross Hotel, also in Ermita. From Angeles City to Subic Bay things get complicated.
The Swagman tourist bus service goes from the Swagman Hotel, Manila, three times a day (11.30am, 3.30pm and 8.30pm) to the Swagman-Narra Hotel in Angeles City (Php500 one way) and then returns to Manila. On Monday, Wednesday, Friday and Sunday the tourist bus goes on from the Swagman-Narra Hotel in Angeles City (10.00am) to any hotel in Subic Bay Freeport or Barrio Barretto (Php400 one way), and then returns from the Swagman Travel office in Barrio Barretto (12.30pm) to the Swagman-Narra Hotel in Angeles City, where it is possible to connect to the tourist bus service to the Swagman Hotel in Ermita, Manila City (8.00am, 12-noon and 3.00pm). In other words, it is not possible to go direct, the same-day from Manila to Subic Bay by tourist bus but it is possible to return from Subic Bay to Manila the same-day.
The Southern Cross tourist bus service leaves the Southern Cross Hotel, Manila, at 3.30pm and goes to the Orchid Inn in Angeles City (Php400 one way) and THE FOLLOWING DAY, at 8.45am, it leaves from the Orchid Inn in Angeles City to the Subic Bay Freeport, Barrio Barretto and Baloy Beach (Php500 one way), terminating at the Wild Orchid Beach Resort on Baloy Beach, i.e. there is no same-day connection from Manila to Subic Bay. However, on the return from Subic Bay, the tourist bus leaves the Wild Orchid Beach Resort at 11.00am and it is possible to connect with the Angeles City to Manila tourist bus service, which leaves the Orchid Inn in Angeles City at 12.45pm, i.e. you can almost certainly return from Subic Bay to Manila the same day.
Not so simple but at least one way doable direct. N.B. If you plan to do this then make sure you book the room-night at the Swagman-Narra or Orchid Inn in advance, both hotels are popular and fill up quickly from day-to-day, especially during the peak season for Philippine holidays, from November to May.
If the tourist bus routes change we hope to be the first to know so check this forum post from time to time for updates.
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