The relief sculptures by <a href="//commons.wikimedia.org/wiki/Creator:Charles_Wheeler_(sculptor)" title="Creator:Charles Wheeler (sculptor)">Charles Wheeler</a> in the sunken garden at the Tower Hill memorial, commemorating the merchant mariners who lost their lives in World War II. 
This images shows reliefs 3 and 4 (counting clockwise from the west).
<a href="//commons.wikimedia.org/wiki/User:Thryduulf" title="User:Thryduulf">Thryduulf</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>