High-quality, large GaN substrates are needed to produce improved optoelectronic and electronic group-III nitride devices. Current growth rates in the m-plane direction for GaN using the basic ammonothermal method are currently 4 to 10 times slower than in the c-direction presenting a challenge to produce large non-polar substrates. Methods need to be found to enhance growth rates in both non-polar and polar directions. One method would involve growing on a plane vicinal to a boule facet which remains flat without faceting into two or more slower growing singular facets during steady state growth. The present work attempts to find such a steady state vicinal plane and investigates the effect of vicinality on the growth rates, crystal quality, surface morphology, and impurity incorporation of the ammonothermally grown GaN crystals. This was done by preparing freestanding, HVPE grown, atomically flat GaN substrates with the following nominal surface off-orientations: (10-10) towards (11-20): 0, 2, 3, 4, 5, 10 deg; (10-10) towards (0001): 1, 2, 5, 10, 15, 28, 47 deg; (10-10) towards (000-1): 2, 5, 10, 28, 47 deg; (11-20) towards (0001): 4, 17, 29, 32, 37 deg; (11-20) towards (000-1): 4, 17, 29 deg. The seed crystals were placed into the hot zone of a 25mm diameter René 41 autoclave, along with polycrystalline GaN held in a Ni-Cr mesh basket, which was placed in the lower temperature zone. Baffles were placed in between the two zones along with sodium metal. The autoclave was filled with ammonia and heated to 500-600°C to produce pressures of 150-250MPa. Six growth runs were performed between six and 35 days after which the autoclave was cooled, the ammonia released, and the crystals removed. Upon investigating surface morphologies using SEM various unique growth regimes and features were found. From preliminary analysis, it appears that there may be a window between on axis m-plane and (10-1-1) in which the surface does not facet, yet it remains to be investigated if it remains dominant during extended steady state growth. Additionally, the surface of all five investigated crystals between on axis m-plane and five degrees towards a-plane appear to have a c-axis component off-orientation of one degrees towards (000-1). The crystals were analyzed for crystal quality using XRD and the resulting FWHMs of the ω rocking curves revealed no improvement in crystal quality, yet values closely duplicating the seed crystal quality were found. Growth rates varied depending on the initial growth orientation. Impurity incorporation as a function of seed crystal orientation using SIMS was analyzed and will be presented. Absorption measurements were performed on the (10-10) towards (11-20) series with a clear increase in absorption in the longer wavelengths for the crystals within 10° of (11-20).