American Tug 34
Built 2001–2011 by American Tugs (Washington)
About the American Tug 34
Researched from public sources for this model. Any individual boat may have been modified or repowered — confirm before relying on any figure.
- Built
- 2001–2011
- Builder
- American Tugs (Washington)
- Length
- 34.42 ft
- Waterline
- 32.75 ft
- Beam
- 13.25 ft
- Draft
- 3.42 ft
- Displacement
- 20,000 lb
- Hull / keel
- semi-displacement
- Propulsion
- inboard
- Fuel
- 400 gal
- Water
- 150 gal
- Holding
- 45 gal
- Bow thruster
- standard
Tank capacities — where the figures come from
-
Fuel 400 gal
“The fuel system holds 400 gallons” — search excerpt (2006), novesea.com · “Two aluminum fuel tanks (400 gallons total)” — search excerpt (2024-2025), fresnelcm.comOne listing for a 2006 American Tug 34 agrees. The builder's standard-equipment sheet for its successor, the 365, also shows two tanks totalling 400, but that's a different model.
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Water 150 gal
“freshwater ... 150 gallons” — search excerpt (2006), novesea.comOne listing agrees. The sheet for the successor 365, a different model, says 120.
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Holding 45 gal
“holding systems hold ... 45 gallons” — search excerpt (2006), novesea.comOne listing agrees; the successor 365 also has 45.
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Water heater unknown
No document for the 2001-11 American Tug 34 was found. For comparison only, American Tug's present-day standard-equipment sheets for its successor models (365, 362, 395) list an 11 gal heater with heat exchanger and 110 V element, but they aren't a source for this model.
Tanks are often replaced or added on older boats — check the tank labels or a survey for yours.
Thrusters and steering — where this comes from
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Bow thruster standard
“Additional features include an Ultraleather salon settee, granite galley counter, transom storage locker, and bow thrust” — review, cdn.denisonyachtsales.com · “That combination makes the bow thruster almost superfluous ... American Tugs are delivered well equipped ... The basic r” — review, passagemaker.com · “The 41 also will feature full walkaround side decks with boarding gates. Like the 34, she will have a bow thruster.” — review, passagemaker.comThe Powerboat Guide text (republished by a broker) lists the bow thruster among the boat's features, and PassageMaker's review counts it as part of a well-equipped delivery with only electronics and dinghy left to choose. Neither is a builder list, but the two reviews agree.
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Stern thruster unknown
American Tug's standard-equipment sheets for 2024-25 models include stern thrusters, but those are later models; nothing was found for the 2001-11 American Tug 34.
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Steering unknown
No builder, review or owners' source on the steering system found.
Thrusters and steering are often replaced — check the units on your boat before ordering parts.
Beamy semi-displacement tug with full-length keel; shares its designer with the Nordic 32 and 37 tugs (distinguished by a reverse-raked windshield). Single-stateroom layout. Bow thruster standard. Single 330 hp Cummins cruises 12-14 knots; range over 1,000 nm at 8 knots. American Tug production is small (under 10 boats a year across models per owners) and the owners' forum is private, so public problem reports are scarce.
Engines fitted
-
Cummins 6BTA5.9-M3 — 330 hp, diesel, single
standard
HMY and PassageMaker both name a single 330 hp Cummins as standard (about 12-14 kn cruise, ~16-18 kn top). A 2003 listing identifies it as a Cummins 6BTA-M3.Sources: hmy.com · passagemaker.com · curtisstokes.net
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Cummins 370 hp — 370 hp, diesel, single
factory option
PassageMaker says a 370 hp Cummins was the upgrade option (fitted on its demo boat).Sources: passagemaker.com
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Cummins QSB 5.9 (common rail) — 380 hp, diesel, single
factory option
A 2004 American Tug 34 listing shows a 380 hp Cummins QSB 5.9 electronic engine.Sources: denisonyachtsales.com
Boats of the same model can differ — check which engines yours actually has before ordering parts.
Generator
PassageMaker's early review mentions room for a generator and minor generator problems in the fleet, and says boats were delivered well equipped (air conditioning for East Coast boats), but not whether a generator was standard. No two boats for sale show the same unit.
Known problems for this model
No well-sourced problem reports found yet.
Engines & parts
Cummins 6BT / 6BTA 5.9 parts: good
Factory standard engine — you entered “Cummins 6BTA5.9-M3”
Mechanically injected 5.9 L inline six from the Cummins B-series truck/industrial family, so base-engine parts are everywhere. Cummins still sells factory ReCon (remanufactured) marine 6BT/6BTA engines (152–210 hp ratings) with a 2-year/2000-hour warranty. Seaboard Marine is the best-known marine specialist, selling aftercooler/heat-exchanger service kits, upgraded raw water pumps and technical guidance; TAD also sells Cummins packages.
Parts sources: Seaboard Marine, Cummins (ReCon 6BT/6BTA), Diesel Pro Power
Common problems (2)
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Aftercooler corrosion letting seawater into the intake cooling
On the turbo-aftercooled 6BTA the seawater-cooled aftercooler core has vertical tubes and an aluminum housing that corrodes from condensate; a leak can put salt water into the cylinders and wreck the engine. Owners pull, clean, grease and pressure-test the core every few years and fit new O-rings.trawlerforum.com · sbmar.com
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Heat exchanger and aftercooler service cooling
Routine seawater-side service (O-rings, gaskets, zincs) is a recurring owner job; kits are sold for it and refilling coolant without trapping air is a common question.sbmar.com · sbmar.com
Service part numbers (5)
| Oil filter | Cummins 3937743 | “| Oil Filter | 3937743 |” — dealer, marineenergy.com.au · “Cummins Oil Filter 3937743 Spin-on type, 3.66" outside diameter, 6.95" height” — dealer, dieselpro.com |
| Fuel filter 6BT 5.9 210 hp (CPL 742) |
Fleetguard FF5052 Replaces FF42000, FS1251 |
“on-engine fuel filter with drain for all 6BT 210 B’s (CPL 742). Replaces the FF42000, FS1251.” — dealer, sbmar.com · “Cummins 6BT Fuel Filter 3931063 FF5052” — dealer, marineenergy.com.au |
| Fuel filter late 6BTA (also late 4BTA and 6CTA) |
Fleetguard FF5285 | “Fleetguard FF5285 Fuel Filter – late 4BTA 6BTA and 6CTA’s” — dealer, sbmar.com · “Cummins 6BTA Fuel Filter 3890017 FF5285 ... suits late model Cummins 6BTA's, 6CTA8.3-M” — dealer, marineenergy.com.au |
| Raw-water impeller seawater pump with 1-1/4 in hose ports (Sherwood M70/M71 type, early 4BT/6BT) |
Sherwood 10615K | “Seawater Pump Impeller | **1-1/4" PORTS** 3908220 10615K” — dealer, marineenergy.com.au · “Cummins Marine Water Pump Impeller 10615K 2 9/16" diameter, 1 5/8" length” — dealer, dieselpro.com |
| Raw-water impeller keyway-shaft pump, 2 in inlet / 1-3/4 in outlet, 11° offset flange (e.g. P1716/P1730 on 6BTA) |
Sherwood 17000K | “**2" inlet & 1-3/4" outlet ports with 11° OFFSET flange** 17000K” — dealer, marineenergy.com.au · “Cummins Impeller for Key Shaft 17000K” — dealer, dieselpro.com |
From the engine maker’s parts lists, or two independent parts dealers. Numbers change with serial number and get superseded — check yours before ordering.
Cummins QSB 5.9 parts: good
Factory optional engine — you entered “Cummins QSB 5.9 (common rail)”
Electronically controlled (common-rail) successor to the mechanical 6BTA; current Cummins dealer network plus marine specialists such as Seaboard Marine supply parts. Electronic diagnostics require dealer tools more often than on the 6BTA.
Parts sources: Seaboard Marine, Diesel Pro Power
Common problems (3)
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Raw water pump leaks cooling
Owners most often report the seawater pump leaking or being replaced around 1000 hours; an improved pump version is available. Some also updated fuel coolers as a precaution.forums.ybw.com
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Aftercooler service and cracking cooling
As with the 6BTA, the aftercooler needs periodic removal and resealing; a cracked aftercooler is generally replaced rather than repaired.trawlerforum.com · facebook.com
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Burnt intake valves / loss of power engine
Seaboard Marine forum threads describe burnt valves and high-rpm power loss on some QSB 5.9s.sbmar.com
Service part numbers (5)
| Oil filter | Fleetguard (Cummins-specified) LF3959 Also: Cummins 3937743 |
“MMK001SK59 QSB5.9 Marine Service Kit ... LF3959 Oil Filter 1” — manufacturer, cummins.com |
| Fuel filter | Fleetguard (Cummins-specified) FF5488 | “MMK001SK59 QSB5.9 Marine Service Kit ... FF5488 Fuel Filter 1” — manufacturer, cummins.com |
| Fuel pre-filter / separator | Fleetguard (Cummins-specified) FS20402 | “MMK001SK59 QSB5.9 Marine Service Kit ... FS20402 FS Filter 1” — manufacturer, cummins.com |
| Drive belt serpentine belt, post-Jan 2008 QSB 5.9 with 21/22SI or 24SI alternator (brown belt) |
Cummins 4981117 | “Cummins Serpentine Belt for QSB 5.9 (post January 2008) 21/22 SI Alternator CPN 4981117 (BROWN)” — dealer, sbmar.com · “4981117 Alternator Belt for Cummins® QSB 5.9 Engine” — dealer, seapowermarine.com |
| Cummins QSB5.9 marine service kit (zincs, oil, fuel and FS filters, minor water-pump kit) | Cummins MMK001SK59 | “MMK001SK59 QSB5.9 Marine Service Kit” — manufacturer, cummins.com |
From the engine maker’s parts lists, or two independent parts dealers. Numbers change with serial number and get superseded — check yours before ordering.
Model sources (6)
hmy.com · trawlerforum.com · passagemaker.com · curtisstokes.net · denisonyachtsales.com · cdn.denisonyachtsales.com
Other American Tug models
- American Tug 41 2005–2009
Researched from public sources. Spotted an error? The sources are listed above — tell us what they got wrong.