If f = 30 kHz and depth difference l has range in the interval [dth=60,R=100] absorption coefficient has range [0.5969 dB, 0.9949 dB]. A(l,f) eventually comes out with in the range of [533.2,1245.4]. For f = 30 kHz noise N(f) comes out to be 1.12×10−5 using this, Attenuation Noise product range is calculated and finally LSNR is in range of [4.52×106,1.06×107] making SQI in range of [0,1.01×105]. This analysis is for dth=60 m but when dth is modified to 40 and 20 value of forwarding function for different nodes would be with larger values of variance. Direct use of values in this range is impractical and is needed to made comparable with other forwarding functions. Hence, in our solution linearized version of SQI is proposed to be used as forwarding function.