To mitigate the adverse channel effects, the probability of successfully transmitting data packets over each path is computed. A routing path that has connectivity from the bottom to the water surface with the highest probability of successfully transmitting data packets is chosen for data routing. This, unlike the usual approach that only considers path selection, further adds reliability in packets routing. The undersea channel is harsh and fluctuating and the properties of a routing link may change after its computation and prior to initiation of information transmission. Therefore, cooperative routing with adaptive power control of relay nodes is added to the RAR protocol that makes the RACAA protocol. The RACAA protocol functions in the same manner as the RAR protocol except that it involves cooperative routing with adaptive amplification. In cooperative routing with adaptive amplification, a relay node increases its transmit power beyond the normal value when error in the data, it receives from source, is greater than 50% (a certain threshold) before further transferring it to destination. The proposed protocols are free of the requirement of nodes' position coordinates, as obtaining such coordinates is challenging in sea as nodes move with ocean currents. Both RAR and RACAA schemes perform better than the counterpart scheme in packets transfer to sea surface as backed by simulation results. To summarize, this paper has the following contributions:* A reliability-aware routing (RAR) protocol is proposed for UAWSNs that considers the connectivity of the complete paths towards water surface rather than finding the conventional one- or two-hops neighbors. In addition, the probability of successfully transmitting a packet is computed for every chosen path. A path that is connected with water surface with the highest probability of successfully transmitting a packet is chosen as the path for data routing. These strategies overcome packets loss and enhance the probability of transferring packets to end destination with low delay as backed by simulation results. * The underwater is a harsh medium with uncertainty. The condition of a routing link may change just before its computation and prior to information transmission, which may corrupt data packets. To counteract the effect of data corruption, cooperative routing with adaptive power control is combined with the RAR scheme that makes the RACAA scheme. In RACAA, a relay node is able to enhance its power level beyond the normal value if it finds that data packets have more than 50% error. With increased power level, data packets are less prone to corruption by sea channel, as backed by simulation results. This strategy is different from the existing cooperative routing schemes where relay advances packets with fixed power and irrespective of channel conditions. * Both RAR and RACAA schemes make use of physical distance calculation using hello packets. This eliminates the need for knowing geographical positions of nodes within the sea as required in the conventional approach, which is challenging and cumbersome as nodes move with ocean tides. * Based on performance evaluation, the RAR protocol can be used for applications involving reliability with time efficiency. That is, the RAR protocol is capable of high packets delivery in a short span of time. This makes it a first choice of underwater applications that require high throughput with minimal latency. Such applications include, for instance, naval warfare, under sea disaster prediction and prevention. On the other hand, the RACAA protocol can be used in applications involving reliability with delay tolerance, which means applications requiring high data throughput without taking into account the high delay associated with RACAA. Such applications include, for instance, sea bed exploration for mine reservoirs, water quality and pollution monitoring.