What is the best alternative to The Cruise Globe on iPhone?

MarineTraffic - Ship Tracking, S tier, #1 in ship tracking.

Is there a free alternative to The Cruise Globe?

Yes: MarineTraffic - Ship Tracking (S tier, #1) is free to download, with in-app purchases.

Yes. 2 apps rank above it in ship tracking: MarineTraffic - Ship Tracking (#1), Boat Watch - Ship Tracking (#2).

The Cruise Globe is S tier, #3 of the 8 tiered apps in ship tracking. Here is everything that competes with it on iPhone, in tier order.

1
MarineTraffic - Ship TrackingS
Free + IAP · ★ 4.7 · 317,156 ratings · score 97
Tracks vessel positions worldwide using AIS data, with voyage history, vessel details, fleet following and weather on.
2
Boat Watch - Ship TrackingS
Free + IAP · ★ 4.5 · 16,715 ratings · score 92
Identifies and tracks boats and ships on a map using a real-time AIS network, with optional alerts and charts.
4
Ship InfoA
Free + IAP · ★ 4.6 · 2,385 ratings · score 89
Reference app for searching commercial ship data, including particulars, AIS positions, owners, and detention reports.
5
Ship TrackerA
Free + IAP · ★ 4.5 · 6,243 ratings · score 89
Travel app that tracks vessels in real time, showing routes, estimated arrivals, port details and a custom fleet list.
6
MyShipTrackingB
Free + IAP · ★ 4.5 · 15,191 ratings · score 71
Vessel tracking app using AIS data to monitor ships, ports, and weather overlays on a map.
7
Ship Finder LiteC
Free download · ★ 4.3 · 22,466 ratings · score 64
Shows live moving ships on a worldwide map using AIS feeds, with an optional augmented reality camera view.
8
Ship FinderC
$4.99 · ★ 4.3 · 23,670 ratings · score 64
Shows live moving ships on a worldwide map using AIS feeds, with search, filters, bookmarks and an AR view.

What is the best alternative to The Cruise Globe on iPhone?: MarineTraffic - Ship Tracking, S tier, #1 in ship tracking.
Is there a free alternative to The Cruise Globe?: Yes: MarineTraffic - Ship Tracking (S tier, #1) is free to download, with in-app purchases.
Does anything rank above The Cruise Globe?: Yes. 2 apps rank above it in ship tracking: MarineTraffic - Ship Tracking (#1), Boat Watch - Ship Tracking (#2).