What size inflatable boat do I need for fishing?

The single biggest reason people end up unhappy with their first inflatable boat isn't the brand, the colour or even the price. It's the size. Buy too small and you're constantly bumping rods, standing on tackle boxes and wishing you had another 40 cm of deck. Buy too large and you're paying for hull you never use, towing more than you need to and burning fuel to move air.

After fifteen years of putting Aussie families and serious anglers into inflatable boats — from Sydney Harbour tinnie replacements to Top End barra rigs — we've seen the same pattern over and over. Fishing size isn't about how big the fish are. It's about how many people are on board, what water you fish, and how much gear rides with you. Get those three right and the length picks itself.

This guide walks you through it the way we'd walk you through it on the phone.

The three numbers that decide your fishing size

Before you look at a single boat, write down three numbers on your phone. These are the only numbers that matter for sizing:

1. How many adults will realistically be on board at once? Not "capacity" — realistic. Two mates plus your teenager is three adults for sizing purposes.
2. What's the biggest water you'll fish? Sheltered estuary, open harbour, offshore inside 5 nautical miles, or genuine offshore?
3. How much gear rides permanently? A fuel tank, a battery, an esky, four rods, tackle bags, a live-bait tank, a small anchor and chain — it adds up faster than people think.

Almost every fishing complaint we hear traces back to a mismatch between these three numbers and the hull that was bought. So let's match them properly.

By angler count: the honest sizing rule

Here's the sizing rule we give friends and family, not the marketing one:

Notice the sweet spot column. That's where the boat still feels roomy on a full day out but doesn't become a chore to launch or tow. For most Australian fishing scenarios, 3.6–4.0 m is the answer. Below 3.3 m you're in tender territory. Above 4.5 m you're in serious bluewater rig territory with the towing bill to match.

By water type: what you'll actually fish

Size isn't just about people. It's about how the hull handles the chop you meet. This is where a lot of buyers get it wrong.

Sheltered estuaries, lakes, protected bays — think Pittwater, Port Stephens inside, Gippsland Lakes, a farm dam, a river system. Anything from 3.0 m upwards will do. You're not fighting chop, you're fighting patience. Prioritise casting room and a dry deck over hull length.

Open harbour and near-shore coastal — think Sydney Harbour proper, Moreton Bay, Port Phillip. You want at least 3.6 m and a catamaran hull. The twin-hull cat design carves through wind chop instead of slapping over it, and the wider beam gives you a stable casting platform when the ferry wash rolls through.

Offshore inside 5 nautical miles — think out through the heads to a close reef, chasing snapper, kingfish, mackerel. You want 4.0 m minimum, ideally 4.0–4.5 m, in a catamaran layout with a 1.2 mm fabric hull. Anything thinner and anything shorter is asking to be uncomfortable on a lumpy afternoon run home.

Genuine offshore or northern remote — a 4.5 m rigid inflatable with 40 hp is the entry point. If you're asking whether an inflatable is enough for genuine bluewater work, the honest answer is: our 4.0–4.5 m boats do it every week in the right hands and the right forecast, but you plan around the weather, not against it.

By gear load: what actually fits

Gear is the silent boat killer. People remember to count anglers but forget to count what those anglers bring.

On a proper day's fishing, a two-angler load looks like this: 25 L fuel tank, cranking battery, 60 L esky with ice and catch, four rods rigged, one tackle bag, one soft cooler with lunch, a landing net, a small anchor with 30 m of rope and 5 m of chain, two life jackets, a small first aid kit, and whatever the day's bait station demands. That's roughly 90–110 kg of gear before you've caught anything.

A 3.3 m boat carries this. It carries it tightly. A 3.6 m boat carries it comfortably. A 4.0 m boat carries it and leaves you room to move around your gear instead of over it. Whenever you're on the fence between two sizes, the extra 30–40 cm almost always pays for itself in day-of-fishing comfort.

Horsepower: the size decision inside the size decision

Size picks the hull. Horsepower picks how the hull actually behaves. For fishing use, our recommended matches are:

• 3.0–3.3 m: 6–9.9 hp (electric or petrol)
• 3.3–3.6 m: 9.9–15 hp
• 3.6–3.8 m: 15–20 hp (this range planes beautifully with 20 hp)
• 3.8–4.0 m: 20–30 hp
• 4.0–4.5 m: 30–40 hp maximum

We rate our Viper series to a 40 hp maximum for good reason: the transom is engineered for it, but more horsepower doesn't always mean more capable. A well-matched 20 hp on a 3.8 m hull will out-fish an under-matched 30 hp on a badly balanced boat all day long.

The mistake almost everyone makes

If we could stop one thing across every phone call and email we take, it would be this: people buy their fishing boat based on the biggest day they'll ever do, not the ninety percent of days they'll actually do.

You'll take the family out once, you'll take four mates out twice, and you'll fish solo or with one mate the rest of the year. Buy for that ninety percent. When the big day comes, you've still got room. When the small day comes, you're not launching a barge by yourself.

Our honest fishing size recommendations

Here's how our current range maps to fishing scenarios:

• Solo tinnie replacement, estuary and lakes: Viper 330 (3.3 m). Enough deck to stand and fish, light enough to launch alone, 15 hp is plenty.
• Two mates, harbour and near-shore: Viper 365 Open Bow (3.65 m). This is our all-round sweet spot and the boat we recommend most often. Catamaran hull, open bow for anchoring bow-first, room for four but perfect for two.
• Family of four, everything from lakes to near-shore: Viper 400 Open Bow or AeroCat 380. The extra 30–40 cm turns "cosy" into "comfortable" the moment kids and gear are involved.
• Serious fishing platform, offshore-capable: Viper 400 Sovereign. Aluminium floorboards, deep-vee catamaran hull, 40 hp — this is the one for chasing pelagics.

What we build them out of, and why it matters for fishing

One last thing that isn't about size but is about the boat lasting long enough for size to matter. Every fishing boat we build uses 1.2 mm German VALMEX® Heavy Plus fabric. That's a 10–12 year service life in Aussie sun and salt. The thin 0.9 mm PVC fabric you'll see on cheaper imports has a 3–7 year service life in the same conditions.

Fishing is hard on boats. Sinkers get dropped. Hook points get dragged. Fillet knives get set down where they shouldn't be. A thicker fabric absorbs all that without complaining. That's why we build to 1.2 mm and not to a price point.

Ready to pick your size?

If you got this far and you're still on the fence, here's the shortcut: call us, tell us your three numbers, and we'll tell you which of our boats fits. No upsell — we'd rather sell you the right 3.6 m boat than the wrong 4.0 m one. That's how you get a customer who buys their second boat from you too.