Comparison

Mamori vs Sea Depth

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Mamori

Features
Read full description

MAMORIアプリは、MAMORI端末を利用して、お子様、ペット、車、身の回りモノなど、気になるものを追跡したいすべての人のためのアプリです。 「MAMORI」を利用すると、次のことができます。 - リアルタイム位置情報の表示 - 移動履歴の閲覧 - 特定の場所に到着したときにタイムリーな通知 - 大切な人を守るためにジオフェンスの作成、管理 - 緊急時にMAMORI端末の位置情報を即座に共有 - MAMORI端末を紛失した場合にビープ音を送信 - 地図表示と衛星写真表示の切替

About

Sea Depth

Visualize detailed underwater terrain with high-resolution bathymetric charts. Gain deeper insights into seafloor structure, contours, and terrain for offshore activities. Includes optional data overlays and waypoint management for enhanced situational awareness.

Highlights
  • High-resolution shaded-relief bathymetry
  • Detailed depth contours with intelligent labeling
  • Optional data overlays (pipelines, bottom composition)
  • GPX waypoint import/export
  • Drift Test tool
  • Offline chart access
Features
Read full description

SeaDepth delivers professional-grade bathymetric charts for anglers looking to add a new level of detail and insight offshore. Built using high-resolution survey data and advanced shaded-relief techniques, SeaDepth reveals underwater structure, contours, and terrain that traditional charts often fail to show. The result is a clearer, more intuitive view of the seafloor - helping anglers and captains better understand offshore environments before and during time on the water. In addition to detailed depth visualization, SeaDepth offers optional data overlays, intelligent contour labeling, waypoint interoperability, and analytical tools that enhance situational awareness offshore. Key Features • High-resolution shaded-relief bathymetry • Detailed, clearly labeled depth contours • Intelligent contour interval scaling by depth range • Pipeline overlay (Gulf of America) • Bottom composition overlays highlighting seafloor characteristics • GPX waypoint import and export for interoperability with other platforms • Drift Test tool to observe drift direction and speed over time • Offline chart access for use beyond cellular coverage • Smooth zooming and panning optimized for offshore use Depth Contours with Intelligent Labeling SeaDepth uses a graduated contour labeling scheme designed to provide maximum detail where it matters most, while maintaining clarity and performance in deeper  depths: • 1-foot contour intervals from 1 to 500 feet • 10-foot contour intervals from 500 to 2,500 feet • 80-foot contour intervals from 2,500 feet to abyssal depths This approach delivers high-resolution insight in shallow and mid-depth areas while avoiding visual clutter in deepwater environments. Overlay Intelligence SeaDepth allows users to enable optional overlay layers such as pipelines and bottom composition data in supported regions, including the Gulf of America. These overlays provide additional context and help users interpret bottom features and structural edges with greater confidence. All available overlay layers are included at no additional charge. Waypoint Management (GPX Support) SeaDepth supports importing and exporting waypoints using the GPX file format, making it easy to move data between SeaDepth and other compatible marine devices, charting software, or planning tools. This allows users to maintain consistent waypoint libraries across platforms. SeaDrift-Drift Test Feature The built-in Drift Test feature helps users evaluate drift behavior by tracking movement over time. This is especially useful when assessing current and wind influence to have more productive drifts. Built for Offshore Reliability Charts, overlays, and waypoint data are stored locally on the device, allowing SeaDepth to function reliably offshore where connectivity may be limited or unavailable. Performance and usability are optimized for real-world offshore conditions. Disclaimer SeaDepth is intended as a supplemental planning and visualization tool only. It is not a substitute for official nautical charts, onboard navigation systems, or prudent seamanship. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

Mamori4 screens
Sea Depth4 screens

Verdict

The call

The clearest difference is in-app purchases: Mamori at none against Sea Depth's 10. Mamori also leads on iOS requirement (13.0 vs 15.0). Sea Depth's advantage is update cadence (every 5 days vs every 5 months). On price, ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Sea Depth sells 10 in-app purchases, starting at $99.99 per year. Mamori asks for nothing beyond the download.

UpkeepUpdate frequency

Mamori ships an update every 5 months, Sea Depth every 5 days. The most recent releases landed on October 3, 2026 and October 28, 2026 respectively.

Scorecard3 real differences · 7 level
Mamori versus Sea Depth: the parameters behind the verdict, then further details
ParameterMamoriSea Depth
PriceFreeFree
Rating—4.2 (16 ratings) — better
Positive reviews—100.0% of reviews
Number of ratings—16 — better
Update frequencyEvery 5 monthsEvery 5 days — better
AdsNoNo
In-app purchasesNo — betterYes
Monetization—Free with in-app purchases
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS13.0 — better15.0
Further details — not scored
Size128 MB106 MB
Age rating4+4+
DeveloperTrackimo LLCSeadepth Charts, LLC

In-app purchases

None

Mamori

No in-app purchases

10 purchases

Sea Depth

Subscriptions1
  • Premium Charts Access7 Days trial$99.991 Year
One-time9
  • Western GOA 50%$150.00
  • Eastern GOA 30%$209.99
  • Cental GOA 20%$239.99
Show 6 more
  • Eastern GOA 20%$239.99
  • Cental GOA$300.00
  • Western GOA$300.00
  • Eastern GOA$300.00
  • Florida-West Coast$300.00
  • South Florida/Northern Bahamas$300.00

Questions

Is Mamori free?
Mamori is free to download, with no in-app purchases.
Is Sea Depth free?
Sea Depth is free to download, with in-app purchases available.
Do Mamori or Sea Depth have ads?
Neither Mamori nor Sea Depth shows ads.
Which is updated more often, Mamori or Sea Depth?
Mamori ships an update every 5 months, and Sea Depth every 5 days. Most recently, Mamori was updated on October 3, 2026 and Sea Depth on October 28, 2026.

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