We study the use of Silicon photo-multipliers (SiPMs) for underwater wireless optical communications (UWOC) and discuss their main interests and drawbacks, compared with photo-multiplier tubes. This comparison is mainly based on practical considerations regarding system implementation and the attainable link span. Presenting an appropriate model for signal attenuation in water and considering the simple On-Off keying modulation, we bring clearance on the real interest of using an SiPM in the UWOC context. We also elucidate the main drawbacks of these components in practice, in particular, regarding the limitation on the transmission data rate, as well as the nonlinear distortion caused on the received signal in relatively short ranges, where the signal intensity is too large.