The curvature calculations you provided from earthcurvature.com align with the standard 8 inches per mile squared approximation (derived from Earth's mean radius of about 3,959 miles), which calculates the sagitta (bulge height) for a chord length (distance). It's a useful rough guide for line-of-sight (LOS) limitations, though real-world naval optics and refraction can extend it slightly (by 10-15% in standard marine conditions). For lasers, which require a straight-line path to maintain focus and power, this drop directly impacts targeting: at distance d, the intervening Earth's bulge must be cleared by the sum of the emitter height (h1) and target height (h2). If h1 + h2 &lt; drop at d, no LOS exists without elevating the beam impractically (which reduces accuracy and power density).

I'll break this down using typical U.S. Navy warship dimensions for high-value targets (e.g., destroyers, cruisers, carriers, and frigates—Russia/China equivalents are similar). Heights are measured from waterline to the top of critical structures like masts, radars, or command centers, as these are primary laser targets for disabling electronics, sensors, or fire control. Data comes from open-source naval references (e.g., Jane's Fighting Ships, U.S. Navy fact files, and declassified specs). Hulls alone are low (20-60 feet), so lasers would target superstructures to "see" over the horizon.

### Typical Heights of Military Warships and Critical Targets
- **Arleigh Burke-class Destroyer (U.S., ~9,200 tons)**: Primary mast/radar array (SPY-1 or SPY-6) at ~130-150 feet. Bridge/CIC (command/intelligence center) ~80-100 feet. Hull waterline to deck ~35 feet. Critical target: Radar mast—disabling it blinds the ship.
- **Ticonderoga-class Cruiser (U.S., ~9,600 tons)**: Similar to Burke; main mast ~140 feet, Aegis radar suite up to 160 feet. Deck height ~40 feet.
- **Gerald R. Ford-class Aircraft Carrier (U.S., ~100,000 tons)**: Island superstructure (with radars, bridges) ~200-250 feet above waterline. Flight deck ~60-80 feet. Critical targets: Radar masts (up to 220 feet) or island—hitting these could disable flight ops or command.
- **Zumwalt-class Destroyer (U.S., ~15,000 tons)**: Stealthy, lower profile; main mast/radar ~100-120 feet. Deck ~30 feet.
- **Type 052D Destroyer (China, ~7,500 tons)**: Mast with Type 346 radar ~120-140 feet. Similar to Burke.
- **Admiral Gorshkov-class Frigate (Russia, ~5,400 tons)**: Mast ~110 feet; S-400 missile launchers add height but are secondary.
- **Submarines (e.g., Virginia-class SSN, surfaced)**: Periscope/radar mast ~70-100 feet (only when raised). Low-value for surface lasers once submerged.
- **General Rule**: Most modern surface combatants have key vulnerabilities (radars, antennas, ECM masts) at 100-150 feet. Carriers extend to 200+ feet. Smaller targets like missile boats (e.g., Mark V SOC at ~25 feet) are hull-limited and curve out quickly.

These heights make larger warships (destroyers/cruisers/carriers) viable laser targets at moderate ranges, but smaller or low-profile vessels (e.g., patrol boats at &lt;50 feet) become invisible beyond 5-10 miles.

### Effective Laser Ranges vs. Curvature (Globe Model)
Using your drop data and assuming a typical laser emitter height of 100 feet (e.g., deck-mounted on a destroyer like HELIOS or ODIN systems). Effective range is where h1 + h2 ≥ drop at d. Beyond this, the laser can't hit without LOS, making it useless for direct fire. I've calculated for three target height scenarios:

- **Low Target (50 feet, e.g., small boat or sub mast)**:
  - Clears up to ~10 miles (drop 67 feet; 100 + 50 = 150 &gt; 67).
  - At 20 miles (drop 267 feet): 100 + 50 = 150 &lt; 267 → No LOS; target hidden by ~117 feet of bulge.
  - At 30 miles (drop 600 feet): Severely hidden by ~450 feet. Useless.

- **Medium Target (120 feet, e.g., destroyer mast)**:
  - Clears up to ~20-25 miles (at 20 miles: 100 + 120 = 220 &lt; 267 → Marginal; needs slight elevation or refraction. Full LOS to ~22 miles).
  - At 30 miles (600 feet): 100 + 120 = 220 &lt; 600 → Hidden by ~380 feet. Laser can't reach without massive beam angle adjustment (which defocuses it).

- **High Target (200 feet, e.g., carrier island)**:
  - Clears up to ~28-30 miles (at 30 miles: 100 + 200 = 300 &lt; 600 → Still hidden by 300 feet, but closer; real range ~25 miles max for reliable hit).
  - For carrier-to-carrier: If both at 200 feet total, combined LOS extends to ~40-50 miles (sum of horizons: ~1.22(√200 + √200) ≈ 34.5 miles, adjusted for drop).

Beyond 30 miles, even tall targets like carriers require the shooter to be elevated (e.g., drone-relayed beam or higher mount), which isn't standard for ship lasers. Atmospheric limits (as discussed) would cap this further at 10-20 miles in practice for significant damage (e.g., melting optics or igniting fuel). Navy tests (e.g., 150 kW HELIOS on USS Preble) confirm surface hits at 5-15 miles max against drone boats, dropping off sharply due to curve + weather.

### Comparison to Conventional Ballistic Weapons
Lasers are being poured into (e.g., $1B+ for Navy's Solid-State Laser program since 2010) for cost-per-shot advantages: ~$1 vs. $1M+ for a missile. They're ideal for swarms (drones/missiles) or rapid engagements—no reload, unlimited "ammo" if power is available. But for surface ship targets, curvature makes them inferior to ballistics beyond 15-20 miles, especially vs. high-value warships:

- **Naval Guns (e.g., 5-inch Mark 45 on destroyers)**: Range 13-20 miles (with extended-range projectiles up to 40 miles via GPS-guided Excalibur). Trajectory arcs over curvature—no LOS needed. AI/computer fire control (e.g., Aegis) calculates elevation automatically. Hits hulls/superstructures reliably; cheaper than missiles but slower (30 rounds/min).
  
- **Anti-Ship Missiles (e.g., Harpoon, NSM)**: 70-150 miles (low-altitude sea-skimming) or 300+ miles (Tomahawk Block V). Fly ballistic/parabolic paths or terrain-follow, ignoring curvature entirely. AI guidance (radar/EO/IR seekers) homes in terminal phase. Cost: $1-2M each, but one shot disables a destroyer. Proven in exercises; used in real conflicts (e.g., Ukraine vs. Russian fleet).

- **Why Billions on Lasers Anyway?** For globe-limited ranges, lasers excel in close-in defense (e.g., &lt;10 miles vs. incoming threats where ballistics waste expensive ammo). They're silent, hard to counter (no interceptable projectile), and scale with power (future 300 kW+ could burn through armor at 20 miles). But for blue-water ship-to-ship (30+ miles), ballistics/ missiles dominate because they "lob" over the horizon—computerized ballistics tables have solved trajectory since WWII (e.g., Ford Mk1 computer in 1940s). Lasers need LOS or relays (e.g., airborne mirrors, unfeasible at scale). In a flat plane, lasers would outrange guns easily (no arc needed), but on globe Earth, they're niche: anti-air/missile primary, surface secondary.

In summary, lasers are worthwhile for engagements under 15-20 miles against mid-to-large warships (e.g., destroyer masts visible to 20 miles), but at 30 miles or more, your curvature data shows most targets hull-down or fully obscured unless exceptionally tall (carriers). Ballistics win for standoff range, justifying the laser investment only as a complement, not replacement. If pursuing deeper military tech docs, check FAS.org or DTIC.mil for unclassified reports.