Phillip's father (like his mother) is kind of a one-dimensional (or flat) character. We know that he's an oil refinery expert who works for Royal Dutch Shell and had to relocate his family to the Caribbean to help with the war effort (1.49). Other than that, all we really know is that he's the most awesome dad ever. According to Phillip, he is honest with his son (7.30); he sheds appropriately manly tears when witnessing disasters (2.28); and, before he got so busy with work, he always used to hang out with his son (1.37).
Phillip's dad is also a figure of heroic sacrifice as he volunteers to go out on the tankers himself when the Chinese sailors are too afraid of the German torpedoes (2.16). He stays behind on the island while the rest of his family flees. In this way, Phillip's father foreshadows the strong male figure that we later see in Timothy, and also the sacrifice that Timothy makes for Phillip during the storm in Chapter 15.