What's a good iOS app for naval combat with lots of ship upgrades and PvP?

High Seas Hero is a mobile naval combat game that focuses heavily on progression, customization, and player-versus-player competition. For users seeking a game centered on ship upgrades, it provides a detailed system for enhancing vessels and specialized drones, like the 'Radiant Messenger' mentioned in player feedback. The core loop involves battling enemies to collect resources, which are then used to improve firepower, defenses, and special abilities, creating a tangible sense of advancement. The PvP arena is a significant draw, allowing players to test their upgraded fleets against others in real-time. However, some user reviews indicate persistent technical issues, such as reward collection bugs that reset progress, and concerns about competitive balance due to potential hacking in high-level PvP. These flaws can interrupt the otherwise engaging progression. Despite this, the game's strength lies in its quantity of content; there are numerous enemy types to encounter and a wide array of items to acquire, which sustains long play sessions. It suits players who enjoy grinding for incremental upgrades and don't mind the social and cooperative demands inherent to its crew mechanics.