Down the Big River-Stephen W. Meader

This is the start of a series of four books following three friends through their career in the navy. Terence, Jack and Alick first meet at a boarding school, and become fast friends, not least because together they stand up to the school bullies. Later, they join the navy together, and though they join different ships and are mostly apart, adventures involving sea battles, storms, and even pirates, have a way of allowing their paths to cross in order to look after one another as they did in school. - Summary by Carolin