Operating from Historic Charter Boat Row at 1801 N Roosevelt Blvd (Amberjack 21) in Key West, Captain Magnus runs Ultra Grand Slam Fishing with a 4.8-star rating from 57 Google reviews. Available 24/7 for flexible scheduling, the operation focuses on serious offshore fishing for big game species.
According to their website at captainmagnus.com and customer reviews, Captain Magnus specializes in trophy fishing, with at least one reviewer mentioning a blue marlin catch—the bucket list fish for many saltwater anglers.
You can reach them at (305) 304-1639. The 24/7 availability suggests they work with tide and condition windows rather than fixed schedules, which matters for targeting pelagic gamefish.
Big game capability and results
Randy O'Connor's son caught a blue marlin on their trip—"the bucket list event" as Randy described it. Landing a blue marlin requires proper equipment, boat capability, and captain skill. The fact that they returned for a second trip and called both "awesome" speaks to consistency.
Comfortable boat for extended offshore runs
Randy specifically mentioned "The boat is very comfortable," which matters on full-day trips targeting fish that may be miles offshore. When you're spending 8+ hours on the water, boat comfort affects the entire experience.
Master-level fishing skills
Randy called the "skipper and mate masters at the art of fishing." For technical big game fishing, that expertise is what separates catching from just hoping.
Crew coordination
Joanne's review mentions both Captain Magnus and Jesse from Irish Cowboy (likely a first mate or associated operation), calling them an "awesome team." Quality first mate work is crucial for big game fishing where multiple lines and quick reactions matter.
With 57 reviews averaging 4.8 stars on Google, the feedback is positive:
Trophy fish capabilities are confirmed. Blue marlin is mentioned specifically, along with references to hammering "beautiful fish" and catching substantial numbers (11 fish in Joanne's trip).
Repeat client satisfaction. Randy's second trip and continued high praise suggest consistent quality experiences.
Professional crew work. References to the mate "not stopping for a moment" and the overall team coordination indicate they run a tight operation.
The smaller review count (57) compared to some other Key West operations isn't necessarily negative—it may simply reflect a focus on fewer, more specialized big game trips rather than high-volume reef fishing.
Anglers with blue marlin or billfish goals - If you're coming to Key West specifically to chase billfish, the confirmed catches and captain focus make this worth considering.
Experienced offshore anglers - The emphasis on "masters" of fishing and trophy species suggests this caters to people who understand and appreciate technical big game fishing.
Groups wanting comfortable boats for long days - The specific mention of boat comfort matters if you're doing full-day offshore trips in open water.
Serious anglers rather than casual family groups - While anyone can fish here, the big game focus and trophy orientation suggest this targets people with specific offshore goals rather than introductory experiences.
Be clear about your goals when you book. Targeting blue marlin looks very different from reef fishing or general offshore work. Captain Magnus needs to know what you're hoping to achieve to plan properly.
Understand that big game fishing can mean long periods between bites. Blue marlin and other billfish don't bite constantly. If you need non-stop action to stay engaged, discuss alternatives like combining trolling with bottom fishing.
Book well in advance for peak billfish season. Prime times for marlin and sailfish see heavy competition for quality boats and captains. If you have specific dates, call early.
Bring quality camera equipment in waterproof protection. Blue marlin and other trophies deserve proper documentation. Make sure you have memory space and battery life for an all-day trip.
Ask about the first mate situation when you book. Joanne's review mentions Jesse, but it's not clear if he's always part of the crew or if it varies. Quality mate work is crucial for big game success.
Be prepared for the physical demands of fighting big fish. A blue marlin can take 30+ minutes to land. If you have back, shoulder, or endurance concerns, mention that when booking so they can set the drag appropriately.
Discuss the 24/7 availability in terms of optimal timing. Marlin fishing may be better at specific tide or time windows. Captain Magnus's flexible schedule should let you fish when conditions favor your target species.
The "Ultra Grand Slam" name refers to catching multiple billfish species in one trip (blue marlin, white marlin, sailfish, spearfish). Ask about the realistic odds for your timing if that's your goal. It's an exceptional achievement that requires both skill and luck.
Source: Google My Business listing and customer reviews for Ultra Grand Slam Fishing, accessed January 2026.
