Implants of MeV B-11, Al-27 and Ga-69 into the <0001> channel of 6H-SiC have been performed and concentration versus depth profiles have been obtained utilizing secondary ion mass spectrometry (SIMS). The experiment shows that the deepest channeled Ga ions reach a depth of 6.6 mum, which is 4 times deeper than the projected range of a random angle implantation, while the deepest channeled B ions only exceed the random projected range by 40%. Measurements at several implantation fluences show that implantation induced damage quench the deep channeling at fluences around 2 and 10x10(13) cm(-2) for Al and Ga, respectively, while only a minor fluence dependence is found in the B implants at fluences up to 2.6x10(14) cm(-2). The ion mass dependence of these effects is explained by the electronic to nuclear stopping ratios. Monte Carlo simulations of the channeling implants have also been performed and good agreements are found between simulations and experimental data.