How to Choose a Water Tank for Overlanding
By Klymit - Official Site | Lightweight Camping Gear | Published: 2026-10-27
Category: How-to Guides
Learn how to pick the right overland water tank by capacity, mounting, and pressurization. Compare 4, 5, and 8 gallon options for your adventure.
Quick Answer
For most overlanders, a 5-gallon tank like the WaterPORT Overlander offers the best balance of capacity and portability. Choose an 8-gallon tank if you need more water for longer trips or group use, and a 4-gallon tank for solo adventures or tight spaces.
Capacity vs. Weight Trade-Off
Water weighs about 8.34 pounds per gallon, so a full 8-gallon tank adds over 66 pounds to your vehicle. That extra weight can affect fuel economy and handling, especially on rough trails. A 4-gallon tank is lighter and easier to move, but you may need to refill more often.
Think about how many people are on your trip and how long you'll be away from a water source. A 5-gallon tank is a sweet spot for two people on a weekend trip, while an 8-gallon tank suits longer expeditions or larger groups.
Mounting and Portability
Overland water tanks need to be secured during travel. The WaterPORT tanks offer mounting options for roof racks, truck beds, or inside the vehicle. Consider how you'll access the tank: a low-profile design can be easier to mount under a rack, while a taller tank might fit better in a bed.
If you plan to move the tank from vehicle to campsite, weight and handles matter. A 4-gallon tank is more portable, while an 8-gallon tank is better left mounted.
Pressurization Options
Pressurized water is a game-changer for rinsing dishes, washing hands, or showering. The WaterPORT tanks offer three pressurization options, so you can choose between hand pumps, battery pumps, or other methods. This flexibility lets you match the tank to your comfort and power availability.
If you want instant high-pressure flow without electricity, look for a tank that supports manual pressurization. If you have a power source, an electric pump can save effort.
Decision Rules for Choosing Your Overland Water Tank
- Trip Duration and Group Size: Estimate 1 gallon per person per day for drinking, cooking, and basic hygiene. For a weekend trip with two people, a 5-gallon tank is usually enough. For longer trips or more people, choose an 8-gallon tank. If you're unsure, err on the side of more capacity for multi-day trips, but remember you can always refill.
- Mounting Space: Measure your roof rack or cargo area. The 8-gallon Weekender is designed for roof racks, while the 4-gallon DayTank is easier to fit in tight spaces. The 5-gallon Overlander offers a low-profile design that works in many setups. Check your vehicle's weight limits before mounting a full tank.
- Pressurization Preference: If you want water flow without batteries or power, choose a tank with manual pressurization like the Overlander. If you have a power source and prefer convenience, consider a tank that supports electric pressurization. Test the pressurization method before a long trip to ensure it meets your needs.
WaterPORT Tank Options
- Overlander Tank - 5 Gallon: The WaterPORT Overlander 5-Gallon Tank provides pressurized water anywhere—no power needed, with three pressurization options for instant high-pressure flow. This is a versatile choice for most overlanders who want reliable water access without depending on batteries or power.
Overlander Tank - 5 Gallon - Weekender Tank - 8 Gallon: The Weekender 8-Gallon Water Tank is built for roof rack mounting or campsite use, keeping you clean and refreshed on longer trips. The larger capacity suits extended adventures or groups, but you'll need to account for the added weight and mounting space.
Weekender Tank - 8 Gallon - DayTank - 4 Gallon: The 4-Gallon DayTank offers multiple spray settings and easy mounting options for rinsing, cleaning, and staying fresh. Its compact size is ideal for solo campers or as a secondary tank for quick tasks without hauling extra weight.
Who Each Tank Fits Best
Best for
- Solo campers or minimalists who need a lightweight, portable tank for quick rinses and cleaning
- Overlanders with limited mounting space or who prefer a low-profile tank
- Groups or long expeditions that need a large water supply and have the roof rack or cargo space to carry it
Not for
- Ultra-light backpackers who need to carry water in a pack, not a rigid tank
- Overlanders who need water for heavy-duty tasks like power washing or filling large RV tanks
