In House of Dragon Sea Smoke Chooses Addam of Hull because he is a bastard son of lord Corlys Velaryon and lives in Driftmark with his younger brother Alyn and works at sea shores collecting crabs.
Addam of Hull does not choose seasmoke but seasmoke in search of her new rider chooses Addam of Hull as new rider as he is bastard son of Lord Corlys Velaryon
Dragonseed Addam of Hull Claims Seasmoke
When princess Rhaenyra Targaryen lost Rhaenys Targaryen and melys during the battle of Rook’s Rest and killed By Aemond and his Dragon Vhagar, she needed more dragons and dragon rider. Prince Jacaerys Velaryon during the discussion says something about Dragon Seeds which is already existed in old book and they learned the concept of Dragon Seeds and how they can claim unclaimed dragons from dragonpit.
In search of Dragonseeds, Rhaenyra targaryen find sir Steffon Darklyn and finds out he has Valyrian blood in him and ask him to claim Seasmoke and she also warns how this can go wrong and you need to be ready to death while claiming dragon and dragon can burn you to death.
Seasmoke Chooses Addam of Hull as His Rider
Sir Steffon Darklyn attempts to Claim Seasmoke but seasmoke burns him to death and flies away from Dragonpit.
After Seasmoke burning Steffon Darklyn to death she flies from dragon pit and finds Addam of Hull collecting crabs along sea shore and chases him and corners him and Seasmoke see’s something in him as he is bastard of lord Corlys Velaryon with Velaryon blood and looks similar to his previous rider Laenor Velaryon.
Addam of Hull Son of Lord Corlys Velaryon
Seasmoke may have chooses Addam of Hull as a new rider as her previous rider Laenor Velaryon is sone of Lord Corlys Velaryon and she finds something similar in both of them ( Velaryon blood) and Qualities that seasmoke needs in her new rider.
What Happens After Addam of Hull Claims Seasmoke
After addam of hull riding Seasmoke, he confronts with princess rhaenyra targaryen face to face along the shores of sea and asks him who are you and how you claimed Seasmoke and he explains he did not choose to ride but seasmoke chooses him to ride and explains his situation.
During this process princess Rhaenyra targaryen finds out he is bastard son of lord Corlys Velaryon and that is the reason seasmoke choose him as new rider and asks him to fight to get her iron throne back and Addam of Hull fights on princess Rhaenyra targaryen side blacks and helps her to claim her iron throne back.