I try not to listen to father frank b/c he's usually right!!
I run a Mirage Plus on my boat. The stern lifting (low rake) props are nice on a 20 Seacraft . . . You'll see when/if you try a mirage plus. Anyways . . . You'll pickup 400 rpm and speed switching to the viper from the rapture (same pitch). Some folks here like the Laser II 19 pitch on their seacraft . . . which is a fast bow lifting prop. I don't think your motor will turn a 19 laser in the recommended RPM range and they don't make a 17 laser. Viper will get your RPM's up . . . but I agree with frank that the mirage plus is a better seacraft prop.