---
title: "Boat Gas Cap — $81K/yr Amazon US Niche (2026) - Flapen"
canonical_url: "https://flapen.com/research/us/sports-outdoors/boat-gas-cap"
last_updated: "2026-08-11T05:34:34.699Z"
locale: en
meta:
description: "Niche score 69/100 · $81K/yr market · 67K searches/yr. A failed launch gate (market size, growth, or returns) keeps it on the watch list. Data updated Jul 2026."
"og:description": "Niche score 69/100 · $81K/yr market · 67K searches/yr. A failed launch gate (market size, growth, or returns) keeps it on the watch list. Data updated Jul 2026."
"og:title": "Boat Gas Cap — $81K/yr Amazon US Niche (2026) - Flapen"
---
# **boat gas cap**
**Worth a look**
Shows a thin review moat (89 avg reviews), but a failed launch gate (market size, growth, or returns) keeps it on the watch list.
Market size 20Growth 95Conversion 60Competition 83Returns 26Price range 86Avg price 95Brand share 86Review moat 96Quality gap 78
**Review moat**
**Incredible****88.7**
avg incumbent reviews — the moat a new listing must climb
**Growth**
**Incredible****+120.1%**
90-day search growth — must beat 0% to launch
**Avg price**
**Incredible****$23.24**
avg listing price — sweet spot $15–$100
**Brand share**
**Great****49%**
top-5 brand share — no brand owns this niche
**Price range**
**Great****$6.87–$78.74**
cheapest to priciest tracked listing — scored on the share inside $15–$100
**Competition**
**Great****32%**
top-5 click share — an open shelf
**Quality gap**
**Great****4.3★**
avg incumbent rating — lower means beatable quality
**Conversion**
**Good****5.2%**
search→purchase rate — share of searches ending in a sale
**Returns**
**Okay****4.9%**
return rate — above 5% kills the launch gate
**Market size**
**Bad****$81K**
$81K/yr · 67K searches
**Signals**[** Trending**](https://flapen.com/research/niches?market=us&signal=trending "Search growth > 100% (90d)") [** No Dominant Brand**](https://flapen.com/research/niches?market=us&signal=no_dominant_brand "Top brand's click share < 20%")
According to Flapen's Amazon United States niche tracking, boat gas cap is a $81K/yr Amazon United States market (67K searches/yr). The top 5 brands hold 49% of demand. Demand peaks in May–Jun–Jul–Aug. Verdict: Worth a look — 69/100.
Data updated Jul 24, 2026 · scored weekly · [~~How we score niches ~~](https://flapen.com/research/methodology)
## **boat gas cap market data**
- **Units sold / yr**
- **3K–3K**
- avg 0–100/product
- **Revenue / yr**
- **$58K–$70K**
- units × avg price
- **Conversion rate**
- **5.2%**
- **Avg BSR**
- **#724**
- **Page quality**
- **0%**
- **Prime**
- **91%**
- **Sponsored**
- **74%**
- **Out of stock**
- **4.0%**
- **Avg brand age**
- **41 months**
- **Avg seller age**
- **177 days**
## **Competition & brand share**
Clicks spread well past the top 5 (32% combined) — an open shelf where new products get seen.
**Brands**
**36 **▲rising
**Sellers**
**139**
**Top-5 brand share**
**49%**
Top 20: 85%
**Top-5 click share**
**32%**
Top 20: 71%
**Open market**
**48%**
- SEACHOICE19% - Perko12% - TUELETFU7% - Kylazer7% - KH8665% - Dairrr Fuuu3%
## **Demand & seasonality**
Weekly Amazon search volume, last 104 weeks — +120.1% search growth over the last 90 days.
3K2KSpike '25Spike '26Prime Day '26 seasonSepDecMarJunAugNovMarMay
Peak months: May, Jun, Jul, Aug · busiest ÷ quietest = 5.1×
[**Open Trend **](https://flapen.com/research/us/sports-outdoors/boat-gas-cap/trend)
## **Top boat gas cap search terms**
- **boat gas cap**25K/yr+129.9%4.5% conv. - **boat fuel cap**8K/yr+82.5%3.6% conv. - **boat gas cap replacement**6K/yr+110.9%2.8% conv. - **pontoon boat gas cap**4K/yr+245.8%2.0% conv. - **marine gas cap**5K/yr+105.7%4.2% conv. - **perko gas cap**5K/yr+117.9%5.7% conv. - **marine gas cap replacement**3K/yr+189.1%3.4% conv. - **vented gas caps for boat**3K/yr+117.6%2.5% conv. - **boat gas tank cap**4K/yr+50.3%3.9% conv. - **gas caps for boats**3K/yr+96.0%2.1% conv. [**All search terms **](https://flapen.com/research/us/sports-outdoors/boat-gas-cap/search-terms)
## **Top boat gas cap products on Amazon**
Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.
0%4%$3K8%$6K12%$10K16%$13K1101001K Reviews — right = deep review moatMarket share (90d) ≈ est. sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)
All 24 tracked products in this niche — three views at once, no toggling.
### **Top sellers**
by 90-day click share
[1**Seachoice Replacement Gas Fill Cap Chrome-Plated Zamak**SEACHOICE**$10.93**4.1★542 rev](https://www.amazon.com/dp/B000XBIOUE) [2**Boat gas cap replacement part including valve cap key**Kylazer**$38.40**4.5★31 rev](https://www.amazon.com/dp/B0FJWDZ43T) [3**2 Inch/50mm Boat Gas Cap Stainless Steel Polished Marine Deck Fill with Chain Fuel/Water/Gas Filler Cover Replacement for Boats Yachts Caravans RVs Trucks - Deck Marine Hardware Accessory (Silver)**KH866**$14.08**2.8★8 rev](https://www.amazon.com/dp/B0FVFYLC2Q) [4**Fuel Deck Fill Cap Replaces 0126DP0BLK for Perko 1313 and 1314 Series for Seachoice 32011 for Ranger Brass Non-Locking Cap 2 Pcs**TUELETFU**$8.85**4.1★160 rev](https://www.amazon.com/dp/B0BG5HTDF1) [5**SEACHOICE Replacement Gas Fill Cap Non-Locking**SEACHOICE**$7.64**3.9★65 rev](https://www.amazon.com/dp/B0006ZCITU)
**~~View all top sellers →~~**
### **Newest**
by launch date
[**0540DPG99A Boat Gas Cap Marine Fuel Cap for Perko 1-1/2 Angled Neck Vented Fuel Fills Chrome Plated Bronze with Chain O-Ring & Wrench**GYUTONG**$35.22**3 rev3mo ago](https://www.amazon.com/dp/B0GWH2NQVG) [**316 Stainless Steel Marine Deck Fill Cap with O-Ring Replaces Compatible with Perko 1313/1314 & for Seachoice 32011 Boat Gas Cap Replacement 1-1/2 Thread for Bass Boats**TurtBluse**$10.93**8 rev4mo ago](https://www.amazon.com/dp/B0GTHYBXPM) [**1-1/2 NPT Thread 0540DPG99A Marine Fuel Cap Replacement Gas Cap with O-ring for Angled Neck Vented Fuel Fills Compatible with 0540/0541/0556/0557 Series Vented Fuel Fills**Xiaoyudou**$35.15**4 rev5mo ago](https://www.amazon.com/dp/B0GK78HZDK) [**Boat Gas Cap Replacement for Peko 0540DPG99A Marine Air Cap Cover Fuel Tank Cap with Airtight Seal UV & Corrosion Resistant Heavy Duty Marine Grade Easy ToolFree Installation**Dozont**$30.55**4 rev7mo ago](https://www.amazon.com/dp/B0GCDJ9KB1) [**0540DPG99A Marine Fuel Tank Cap for Perko 1-1/2 Vented Gas Deck Fill Includes Wrench O-Ring & Chain**Succell**$36.01**8 rev7mo ago](https://www.amazon.com/dp/B0G7T25DWZ)
**~~View all new products →~~**
### **Trending**
90-day click momentum
[**Boat Gas Cap Replacement for Peko 0540DPG99A Marine Air Cap Cover Fuel Tank Cap with Airtight Seal UV & Corrosion Resistant Heavy Duty Marine Grade Easy ToolFree Installation**Dozont**$30.55**4.4★**▲ 142%**](https://www.amazon.com/dp/B0GCDJ9KB1) [**316 Stainless Steel Marine Deck Fill Cap with O-Ring Replaces Compatible with Perko 1313/1314 & for Seachoice 32011 Boat Gas Cap Replacement 1-1/2 Thread for Bass Boats**TurtBluse**$10.93**3.8★**▲ 141%**](https://www.amazon.com/dp/B0GTHYBXPM) [**0540DPG99A Boat Gas Cap Marine Fuel Cap for Perko 1-1/2 Angled Neck Vented Fuel Fills Chrome Plated Bronze with Chain O-Ring & Wrench**GYUTONG**$35.22**5.0★**▲ 139%**](https://www.amazon.com/dp/B0GWH2NQVG) [**1-1/2 NPT Thread 0540DPG99A Marine Fuel Cap Replacement Gas Cap with O-ring for Angled Neck Vented Fuel Fills Compatible with 0540/0541/0556/0557 Series Vented Fuel Fills**Xiaoyudou**$35.15**5.0★**▲ 116%**](https://www.amazon.com/dp/B0GK78HZDK) [**2 Inch/50mm Boat Gas Cap Stainless Steel Polished Marine Deck Fill with Chain Fuel/Water/Gas Filler Cover Replacement for Boats Yachts Caravans RVs Trucks - Deck Marine Hardware Accessory (Silver)**KH866**$14.08**2.8★**▲ 79%**](https://www.amazon.com/dp/B0FVFYLC2Q)
**~~View all trending →~~**
## **What buyers say about boat gas cap**
What buyers praise and complain about, mined from review topics.
### **What buyers love **
**Size-Overall**44%
*“Exact fit”*
**Quality-Overall**13%
*“Excellent quality, perfect fit, and a solid seal every time”*
**Advertised Vs Actual Product**8%
*“As advertised”*
**Value For Money**3%
*“Its affordable”*
**Ease Of Use**3%
*“is easy to use”*
**Leak-Proof**2%
*“it does seem to seal just fine”*
**Durability**2%
*“boasts excellent durability”*
**Material Quality**2%
*“The material is dense and corrosion-resistant, ensuring the threads won't warp or cross-thread even after seasons under a blistering sun”*
**Assembly/Installation**2%
*“Easy to install”*
**Design-Overall**2%
*“has a pleasing design”*
### **What buyers complain about **
**Size-Overall**25%
*“Super tiny”*
**Quality-Overall**13%
*“Didn't like the quality”*
**Leak-Proof**5%
*“One of the most common causes of problems with modern engines in boats or cars is a gas cap that is leaking air”*
**Durability**5%
*“Broke before first use”*
**Advertised Vs Actual Product**5%
*“Not a good description”*
**Add-Ons/Attachments**4%
*“Bottom not attached good”*
**Rubber Quality**4%
*“The rubber gaskets were not even installed”*
**Compatibility-Overall**3%
*“Does not fit old Sea Ray boats”*
**Defective Material/Parts**3%
*“The center piece falls off”*
**Functionality-Overall**3%
*“does not work”*
### **Top return reasons **
**Size-Overall**86%
**Compatibility-Overall**4%
**Advertised Vs Actual Product**3%
**Defective Material/Parts**2%
**Functionality-Overall**1%
**Leak-Proof**1%
**Value For Money**1%
**Assembly/Installation**1%
**Quality-Overall**1%
**Software/Application**0%
## **Common questions**
- **Is boat gas cap profitable to sell on Amazon United States?**
- The niche generates $81K/yr across 46 tracked products. 1 of 16 products launched in the last 360 days are still selling. 90-day search growth is +120.1%. Flapen's verdict: Worth a look (69/100).
- **How competitive is the boat gas cap niche?**
- 36 brands and 139 sellers compete. The top 5 products take 32% of clicks and top 5 brands hold 49% of demand.
- **What do buyers complain about in boat gas cap?**
- Top complaints mined from reviews: Size-Overall, Quality-Overall, Leak-Proof. The return rate is 4.9%.
- **When does demand for boat gas cap peak?**
- Demand peaks in May–Jun–Jul–Aug; the busiest month runs 5.1× the quietest.
- **What does it cost to enter the boat gas cap niche?**
- Listings span $6.87–$78.74; the average listing price is $23.24 (sweet spot $15–$100). The average incumbent carries 89 reviews — the moat a new listing must climb.
## **Related niches in Sports & Outdoors**
- 74 [**hydrogen water**](https://flapen.com/research/us/sports-outdoors/hydrogen-water)$6.6M/yr-20.2%**Worth a look**- 74 [**england soccer jersey**](https://flapen.com/research/us/sports-outdoors/england-soccer-jersey)$141K/yr>1,000%**Worth a look**- 74 [**argentina jersey**](https://flapen.com/research/us/sports-outdoors/argentina-jersey)$309K/yr>1,000%**Worth a look**- 74 [**frisbee**](https://flapen.com/research/us/sports-outdoors/frisbee)$1.9M/yr+59.7%**Launch it**- 75 [**trampoline basketball hoop**](https://flapen.com/research/us/sports-outdoors/trampoline-basketball-hoop)$2.3M/yr+49.2%**Launch it**- 75 [**golf glove**](https://flapen.com/research/us/sports-outdoors/golf-glove)$4.1M/yr+62.5%**Launch it**[**All Sports & Outdoors niches **](https://flapen.com/research/us/sports-outdoors)