The top bird is a male, bottom bird is a female. These birds stayed around the pool, remaining with the ship all the way to Dutch Harbor, Alaska. Canon PowerShot SX50 HS..
References:
Brazil, M. (2009). Birds of East Asia. Princeton Univ. Press.
Clement, P. & Arkhipov, V. (2017). Brambling (Fringilla montifringilla). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/61288 on 30 June 2017).
Clement, P., A. Harris, and J. Davis. 1993. Finches and Sparrows: An Identification Guide. Princeton Univ. Press, Princeton, N. J.