  Under Water Sensor Networks (UWSN) have different characteristics than
terrestrial sensor networks, so routing protocols developed for terrestrial
networks are not suitable for UWSN. Underwater routing is comprehended by the
underlying network architecture and design of sensor nodes. Therefore,
efficient routing protocols need to be developed for UWSNs. We present a
Routing scheme based on routing factor (Rf) which is a function of distance and
residual energy. We also define Energy Scale Value to rationalize the available
energy to take heterogeneity in energies into account. The algorithm routes a
packet from one node to another by computing Rf for each neighboring node and
selecting the node with minimum Rf as forwarding node, thereby providing an
energy balancing mechanism among a set of candidate forwarding nodes. We have
also included priority packets in our algorithm which are forwarded in a way so
as to reduce the end to end delays between the packets and at respective nodes.
Simulations of our proposed routing algorithm shows improvement in terms of
network lifetime and number of packets delivered. Our simulations show
improvement in lifetime by a factor of 2 when analyzed with Sector Based
Routing(SBR-DLP).
