Measurements are made of vortex-induced vibration of an elastically supported circular cylinder in water with reduced velocity $(U/fnD)$ from 2 to 12, damping factors $(\zeta )$ from 0.2% to 40% of critical damping, mass ratios $(m/\rho D2)$ from $\pi /2$ to $\pi /17$, and transverse, inline, and combined inline and transverse motions at Reynolds numbers up to 150,000. Effects of mass, damping, Reynolds number, and strakes on vortex-induced vibration amplitude, frequency, entrainment, and drag are reported.