Deep sea trolling is one of the most efficient high-volume fishing methods available in Old School RuneScape’s Sailing content. When executed correctly, it offers strong experience rates, exceptional fish-per-hour output, and a relaxed gameplay loop once routes and depths are mastered, making it especially appealing for players looking to progress efficiently without relying solely on options like buy OSRS gold. This guide covers the optimal setup, crew management, inventory preparation, depth control, and best fishing locations for every shoal type.

Skill Requirements and Boat Preparation

For optimal results, 84 Sailing is strongly recommended. This unlocks the best fishing boat facilities and allows for efficient crew assignments. You will also need between 69 and 91 Fishing, depending on which fish you intend to target. Before starting, ensure your fishing boat is properly constructed with an optimized layout, including trolling nets and a sufficient cargo hold.

To operate with three crew members simultaneously, you must have at least 70 Sailing. Running fewer crew significantly reduces efficiency and is not advised for deep sea trolling.

Crew Management and Assignments

Your crew setup is critical. One crew member should prioritize Helmsmanship and be assigned to the helm to control ship movement. Spotter Virginia or Ex-Captain Sciad at level three Helmsmanship is sufficient for this role.

The remaining two crew members should prioritize Deck Handiness and be assigned to the chump spreader and one trolling net. Jolly Jim and Cowboy Jenkins both perform well here with four Deck Handiness. You will personally man the second trolling net, as this yields better results than rod fishing, which is significantly less efficient during trolling.

Inventory and Cargo Optimization

Bring appropriate bait based on your target fish. Use fine fish offcuts for higher-tier fish and regular fish offcuts for lower-tier fish. These are easily obtained by using a knife on any fish.

Fish crates are essential for maximizing storage. Each crate holds 10 fish, allowing a 200-slot cargo hold to store up to 2,000 fish. To craft fish crates, create a camper crate using a camper log, chisel, adamantite nails, and a hammer. Then combine the crate with ice coolers purchased from Slayer Masters.

Optional utility items may be brought for ocean encounters such as giant clams, but these are not required for core trolling efficiency.

Net Management and Catch Rate Optimization

Once aboard, quick deposit your bait and fish crates into the cargo hold. Assign crew roles through the Sailing interface, then begin trolling. Actively clicking your trolling net reduces the catch cycle from four ticks to two ticks, effectively doubling your catch rate. This is one of the most important optimization techniques and should be used whenever possible.

Depth Control and Plugins

Successful trolling depends on matching net depth to fish depth. Currently, no dedicated trolling plugin exists, but the Watchdog plugin can be configured to provide overhead notifications indicating whether you are too shallow, too deep, or at the correct depth. This significantly reduces guesswork and increases consistency.

Mobile players can rely on wave visuals and in-game descriptions to identify depth levels. Fish shoals follow fixed routes, so memorization and ground markers are also highly effective.

Shoal Routes and Best Locations

· Giant Krill: Located east of Pest Control. Always shallow depth and remain stationary for approximately 90 seconds, making them highly AFK-friendly.

· Haddock: South of Aldarin near the Shivering Atoll. Also remain at a fixed depth but stop for about one minute per location.

· Yellowfin Tuna: Near Deep Fin Point. Alternate between shallow and moderate depths at each stop and halfway point.

· Halibut: South of Deep Fin Point. Identical depth behavior to Yellowfin. Route is tighter and requires careful navigation.

· Bluefin Tuna: Further south near Sunbleached Island. Cycle through shallow, moderate, and deep depths at both stops and halfway points.

· Marlin: North of Weiss. Extremely fast-moving shoals with only 30 seconds per stop and three depth changes. Best tackled with higher-tier ships and defensive hulls due to hostile encounters.

Final Notes

Deep sea trolling rewards preparation and attention to detail. Once routes are marked and depth changes understood, the method becomes consistent, profitable, and efficient, making it an excellent option for players looking to steadily build resources or supplement their income alongside options such as cheap OSRS gold. Focus on correct crew assignments, spam-clicking your net, and mastering depth transitions to maximize results. With practice, deep sea trolling becomes one of the most reliable fishing methods in Old School RuneScape.