ShowShark for Sailors and Cruisers

Stream Your Entire Movie and TV Library on a Boat With No Internet

You left the marina three days ago. The anchorage is beautiful, the kids are sunburned, and the nearest cell tower is somewhere over the horizon. Everyone wants to watch a movie tonight, but Netflix requires internet you do not have, and the hard drive full of MKV files means one person squinting at a laptop screen.

ShowShark turns your Mac into a media server that streams your entire movie, TV show, and music library to every iPhone, iPad, Apple TV, and Mac on your boat's WiFi network. It works completely offline. No internet connection required, no cloud account, no authentication server to phone home to. If your boat has power and a WiFi router, ShowShark works.

Why Sailors Need a Local Media Server

Cruising means extended periods without reliable internet. Coastal hops between anchorages, offshore passages, and remote island landfalls all share the same problem: streaming services do not work without a connection, and satellite internet (even Starlink Maritime at $250+/month) is expensive, metered, and unreliable in rough seas.

The common workarounds are frustrating:

• Downloaded Netflix and Disney+ content expires after a few weeks and cannot be shared between devices. Each family member has to manage downloads separately on each device. Storage fills up fast.
• Hard drives full of movies work for one person on one laptop, but there is no easy way to browse a library, pick a movie, and stream it to a tablet in the V-berth or an Apple TV in the salon.
• Plex Media Server is the most popular media server software, but it requires internet access for authentication. Without a connection, Plex enters a degraded offline mode that limits you to a single user with no new device pairing. Cruisers on forums report being "left with a crippled, one-user experience" after leaving the dock.

ShowShark was built to work without internet from the ground up. There is no degraded offline mode because there is no online mode to degrade from. The server and clients communicate directly over your local network.

How It Works on a Boat

The setup is simple:

1. Connect a Mac to your boat's WiFi router. A Mac mini M4 is ideal; it draws just 3-4 watts at idle, comparable to an LED light. It runs 24/7 off your house battery bank without any meaningful impact on your power budget. A MacBook works too, especially if it doubles as your boat laptop.
2. Point ShowShark at your media. Plug in an external drive (or connect your NAS) with your movie and TV collection. ShowShark scans it, fetches metadata and artwork (do this at the marina while you have internet), and builds a browsable library with posters, descriptions, cast information, and Rotten Tomatoes scores.
3. Open ShowShark on any Apple device. iPhones, iPads, Apple TVs, Vision Pros and Macs discover the server automatically via Bonjour. No IP addresses to type, no port numbers to remember. Pick a device, open the app, and your library appears.
4. Press play. ShowShark transcodes any video format in real time using Apple's hardware video encoder. MKV, AVI, Blu-ray rips; every file plays on every device without pre-conversion. Adaptive bitrate adjusts quality automatically based on your WiFi conditions.

That is the entire setup. No terminal commands, no Docker containers, no configuration files. If you can plug in a hard drive and connect to WiFi, you can run ShowShark.

What Your Evenings Look Like With ShowShark

The kids scroll through the library on an iPad in the forward cabin and find their cartoon channel. ShowShark's virtual TV channels play scheduled programming from your own library; cartoons in the morning, movies in the evening, whatever you configure. The channel plays continuously, just like real TV, so they do not need to pick something new every 22 minutes.

You and your partner browse the library on an Apple TV connected to the salon TV. The interface shows posters, ratings, cast, and descriptions for everything in your collection. You use the "By Feel" discovery feature to find something that matches your mood; a light comedy, something under two hours. ShowShark narrows it down from your library using a guided selection process, and you are watching in under a minute.

Background music plays from your music library through the cockpit speaker connected to an iPhone, with album art, lyrics, and audio visualizers on screen.

Everyone is watching or listening to something different, on different devices, from the same server, over the same WiFi network, with zero internet.

Power Consumption: The Number That Matters on a Boat

Every watt counts on a cruising sailboat. Running an inverter to power a desktop computer is wasteful; a traditional PC might draw 50-100 watts, eating into battery reserves that you need for refrigeration, navigation instruments, and anchor lights.

The Mac mini M4 changes this equation. At 3-4 watts idle and 10-15 watts while actively transcoding video, it sips less power than a typical chart plotter. On a boat with a 400Ah lithium battery bank and 400 watts of solar, the Mac mini is a rounding error in the daily power budget. It can run 24/7 for weeks without concern.

A MacBook is equally viable. It charges from the same USB-C outlets you already have on the boat, and its built-in battery means it keeps running through brief power interruptions when the inverter cycles off.

No Internet, No Problem

ShowShark does not need internet for any core function:

• Server discovery uses Bonjour (mDNS), which operates entirely on your local WiFi network. Clients find the server automatically.
• Authentication is a password stored on the server. No cloud account, no token refresh, no license check phoning home.
• Playback is a direct WebSocket connection between the client and server over your boat's WiFi. All transcoding happens locally on the Mac.
• Library browsing uses metadata and artwork that were fetched and cached when you were last connected to the internet. Once scanned, the library is fully self-contained.

The only features that benefit from an internet connection are fetching metadata for newly added media and checking for software updates. Both happen automatically whenever you reach a marina or a café with WiFi.

Remote Access When You Reach Shore

When you do have internet; at a marina, anchored near a coastal town, or through a satellite connection; ShowShark's built-in remote access lets family and friends connect to your server from anywhere. No port forwarding on the marina's router, no VPN configuration. ShowShark uses an embedded encrypted tunnel that works through any network, including marina WiFi with captive portals and restrictive firewalls.

What You Need

• A Mac. Mac mini M4 ($499) for a dedicated always-on server, or any MacBook you already own.
• An external drive. SSD recommended for a boat (no moving parts, vibration-resistant). A 2TB SSD holds roughly 400-800 movies depending on quality.
• A WiFi router. You already have one on your boat. ShowShark works with any standard WiFi network.
• Apple devices for playback. iPhones, iPads, Apple TVs, Macs, Apple Watch, or any device with a web browser.
• ShowShark Server license. One-time purchase. No subscription, no recurring fees.

Compared to the Alternatives

Start Streaming Before You Leave the Dock

Set up ShowShark at home or at the marina while you have internet. Scan your library, let the metadata load, and verify everything plays. By the time you cast off, your entire media collection is ready to stream to every device on board; no internet required, no subscriptions, no hassle.

Your boat already has the WiFi network. Your family already has the Apple devices. ShowShark is the piece that connects them.