Who ruled the seas during Second Punic War?

Aug 2019
Topanga California
The Romans were dominant at sea during the Second Punic War. The Carthaginians generally fielded only small fleets, and in the case of the larger fleet of Bomilcar, this particular admiral avoided a sea battle with the Romans when it was offered to him. Carthage's empire at the start of the Second Punic War represents a unique phase in their history that transcends their usual modus operandi of mercantile dominance. From 241 to 237 Carthage lost their control over Sicily, Sardinia and Corsica, and they lost their naval dominance. This created the possibility of a new approach to empire, and this possibility was seized by Hannibal's father, Hamilcar Barca. Hamilcar came to dominate Carthaginian politics over the course of Carthage's war with the Libyans and mercenaries (241-237). He saved Carthage from this existential threat (worse than the threat posed at that time by Rome), and thus won political supremacy for himself, his political allies (some of whom he made into relatives), and ultimately his sons. He won Carthaginian support for an expedition into Spain designed to conquer much of the region, and to secure direct control over mineral wealth (especially silver) and Spanish military manpower. He even founded a new city, Acre Leuke, and his successor Hasdrubal (his son-in-law) founded New Carthage, married a Spanish princess and had Spanish tribal leaders proclaim him Strategos Autokrator. Hannibal too married a Spanish princess, and the Barcids appear to have depicted themselves on coins, the first Carthaginian politicans to do so. That is, they were creating a personal empire with Carthaginian backing. Hamilcar, Hasdrubal and Hannibal campaigned throughout Spain, fighting the Tartessiani, Turdetani, Orissi, Carpatani and Vaccei, with Hannibal penetrating into northern Spain. Hoyos, in Unplanned Wars (1998), on the origins of the First and Second Punic Wars, points out that Hannibal's campaigns from 221 to 219 were so far reaching that they threatened the Ebro Accord agreed between Hasdrubal and Rome in c. 226, whereby Hasdrubal agreed not to cross the Ebro River in northern Spain. As Hoyos points out, in 226 the accord probably seemed quite reasonable, since Hasdrubal's forces had not, as far as we can tell, crossed north of the Tagus. By 220, when Roman envoys pressed Hannibal to agree to the old accord, Carthage's presence in Spain had already drastically increased. The Barcids also preserved support at home through marriage alliances and the sending home of silver, spoils and gifts. It is notable that the Barcids' biggest enemy at home, Hanno the Great, is depicted in Livy's account as being decidedly powerless against the Barcid faction. Therefore, the empire of 219 BC was not the same empire that Carthage had traditionally possessed. Carthage's attention was now on the army and landward expansion in Spain. This was a more expansionist and more militaristic empire than the mercantile and naval hegemony of old. For more on this topic, see Hoyos 2003, Hannibal's Dynasty.
I would say this is very accurate and interesting, I definitely think it's not a simple yes/no answer to that question and this post illustrates why.