Specialty & Marine Hoses

For a gasoline powered pleasure boat in the United States, the line you want is marked USCG Type A1 and built to SAE J1527, which is the standard federal fuel system rules for small craft are written against. Three markings tell you almost everything:

• Type A means the hose passed a 2.5 minute open flame fire test, which is what makes it acceptable in an engine compartment
• Class 1 means it is intended for a fuel feed hose that stays full of fuel, rather than a fill or vent run
• The -15 suffix means a low permeation rating of 15 grams per square meter per 24 hours, the tighter limit introduced under EPA evaporative emission rules

Every marine fuel hose in this Evil Energy collection is built to SAE J1527 Type A1-15 and also references ISO 7840 Type A1 and NMMA/CE acceptance. If you want to read the federal definitions yourself, they sit in 33 CFR 183.540: https://www.ecfr.gov/current/title-33/chapter-I/subchapter-S/part-183/subpart-J/section-183.540

"Coast Guard approved" is loose shop language. The Coast Guard does not approve hose brands; it defines hose types, and a compliant hose is one carrying the correct type marking. Here is what each one means in practice:

• A1-15: fire tested plus the lowest permeation limit at 15 g/m²/24h. Usable anywhere on a gasoline boat, including the feed line and the engine compartment. This is what you want by default
• A1: fire tested, older 100 g/m²/24h permeation limit. Still seen, but superseded for new fuel distribution runs
• A2: fire tested but 300 g/m²/24h. Intended for fill and vent lines that do not sit full of fuel, not for feed
• B1 and B2: not fire tested. Typically limited to diesel or above deck outboard use where a fire rating is not required

The practical takeaway: if a listing only says "marine hose" without a type marking printed on the hose itself, you cannot verify what you bought. Evil Energy publishes the A1-15 designation on every marine feed line in this collection. For the recreational boat standard that mirrors these rules, ABYC H-24 is the reference: https://abycinc.org/

Match the hose ID to the fitting or barb you are leaving in place, not to the old hose's outside diameter, which grows as the cover swells with age. The three marine sizes cover most of the recreational fleet:

• 1/4 inch: small outboards, portable tanks, kicker motors
• 5/16 inch: the most common size on mid range outboards and many primer bulb assemblies
• 3/8 inch: larger outboards, inboards, and longer runs where flow restriction matters

Then place it by circuit. Tank to engine gasoline feed takes the A1-15 marine fuel hose. Anything inside the tank takes the SAE 30R10 submersible fuel hose, available in 5/16 and 3/8. Drum, tote, and transfer pump work takes the fuel transfer hose in 3/4 or 1 inch ID with NPT ends already fitted.

One detail people miss: check your minimum bend radius against the tightest turn in your run. Published figures on the 10FT marine line are 65mm at 1/4 inch, 75mm at 5/16 inch, and 80mm at 3/8 inch. A hose forced tighter than its radius will kink and starve the engine, and no clamp will fix that.

The A1-15 marine fuel hose is listed as compatible with gasoline, diesel, E85 ethanol, biodiesel, and blended fuels. The SAE 30R10 submersible hose covers gasoline, diesel, B100 and B20 biodiesel, E10 to E85, oil, and mineral spirits. The fuel transfer hose covers gasoline, diesel, B20 and B100, kerosene, E10 to E100, mineral spirits, and oils.

Pressure is the part to think about carefully. These lines carry a 300 PSI working pressure rating on the marine and submersible hose and 150 PSI on the transfer hose, which is comfortable for carbureted and low pressure feed circuits. For a high pressure EFI supply line, where a rigid, near zero permeation barrier and AN style mechanical ends are the right answer, move to PTFE hose rather than rubber. If you are unsure which side of that line your build sits on, the pressure spec on your pump or regulator is the deciding number.

Brand names aside, durability in this category comes down to four things you can verify on any listing before you pay:

• Printed type marking: does the hose itself carry a USCG Type and SAE J1527 designation, or does the seller only claim it in the description
• Layer construction: a genuine low permeation build uses a barrier layer, not just thicker rubber. Reinforcement type also matters, with polyester braid on the marine line and stainless steel braid on the submersible
• Burst to working ratio: 900 PSI burst against 300 PSI working on the marine hose is a 3 to 1 margin, which is the number that tells you how much headroom you have
• Cover rating: UV and weather resistance on the outer layer is what determines whether the cover checks and cracks after two seasons in the sun

On replacement, do not wait for a drip. Squeeze the line near every clamp and fitting. If it feels hard and glazed rather than pliable, if the cover shows fine surface cracks when you flex it, if the printed marking has worn off entirely, or if you smell fuel in a closed compartment, the line is done regardless of age. In tank hose is the one most people forget, and it is also the one that fails silently.