Defender Waterfall has been on trial with Tranmere and played for the club during their 6-2 friendly win over Heswall, as well as the behind closed doors match against Wrexham.
Described by manager Ronnie Moore as being "tall and talented", Waterfall is a defender most likely to play at centre-back.
The signing of the Yorkshireman means Tranmere have now brought five players to the club this summer.