This paper attempts to explain the observed phenomenon of acoustic reflection from an array of “soft” tubes in an aqueous medium. [W. J. Toulis, J. Acoust. Soc. Am.29, 773(A), 1021–1026, 1027–1033 (1957)] in terms of fundamental array and diffraction theory. Both diffraction and radiation effects are investigated for infinitely long cylindrical tubes of circular cross section as a function ofs/randks. Forks(s/r)−2<1, zero and first‐order diffraction terms together with the corresponding radiation terms suffice. Furthermore, forkr<0.3, the zero‐order radiation term is dominant. Hence, a simple solution for the surface velocity of the typical tube of an infinite array can be found by applying Newton's second and third laws to the tube surface. The infinite series thus obtained bears a strong resemblance to the Fresnel integral. Machine computation is used in a novel way to estimate the sum of this series.