Snapper vs Tuna rail: which Rob Allen speargun for Thai reefs?

If you are picking your first serious Rob Allen or upgrading from a pole spear, the choice almost always comes down to two lines: the Snapper railgun and the Tuna railgun. I have shipped both into every region of Thailand for years. Here is the real answer, with receipts.

The short version

The Snapper is a single-band 14mm rubber gun with a 7mm shaft, built for reef work and fish up to roughly 10 kg. The Tuna is the same frame philosophy stepped up: single-band 16mm rubber, 7.5mm shaft, more power and more penetration for bigger fish, deeper dives, and bluewater shots.

If you dive the Gulf side, mostly shore and boat day trips, visibility 5 to 12 metres, reef fish and the occasional trevally, you want a Snapper.

If you run Andaman bluewater, drop offs, wahoo or dogtooth territory, or you are hunting Spanish mackerel from a kayak at 18 metres, you want a Tuna.

The SKUs, size by size

Snapper railgun line

SKU	Length	Rubber	Shaft
RGSNP08	80 cm	14 mm	7 mm
RGSNP09	90 cm	14 mm	7 mm
RGSNP10	100 cm	14 mm	7 mm
RGSNP11	110 cm	14 mm	7 mm
RGSNP12	120 cm	14 mm	7 mm

Retail in Thailand runs roughly 8,500 to 11,500 THB depending on size, rigged with line, shock cord and a muzzle bungee. That is the all-in price, shipped to your door in 3 days.

Tuna railgun line

SKU	Length	Rubber	Shaft
RGTUN08	80 cm	16 mm	7.5 mm
RGTUN09	90 cm	16 mm	7.5 mm
RGTUN10	100 cm	16 mm	7.5 mm
RGTUN11	110 cm	16 mm	7.5 mm
RGTUN12	120 cm	16 mm	7.5 mm
RGTUN13	130 cm	16 mm	7.5 mm

Retail roughly 11,000 to 15,500 THB. Same build quality, more thump, more range, heavier in the hand.

What actually changes between 14mm and 16mm rubber

The jump from 14mm to 16mm rubber is not cosmetic. It is a meaningful step in stored energy. With the 16mm you get noticeably flatter trajectory at range, better chance of a full pass-through on dense-bodied fish like Spanish mackerel or big trevally, and a bit more recoil. The 7.5mm shaft stays straighter on hard shots into bone.

The trade is loading effort. If you have a narrow chest, shorter arms, or limited loading technique, the 16mm on a 110 or 120 becomes real work. A lot of new spearos think they need the power of a Tuna and end up under-loading it. A well-loaded Snapper out-shoots a badly-loaded Tuna every time.

Use case one: reef, Koh Samui or Koh Tao day trips

Target species: snapper, grouper, small to mid trevally, parrotfish (where legal), the occasional barracuda. Average shot distance 2 to 4 metres. Fish rarely over 8 kg.

Pick: Snapper 90 or 100. The RGSNP09 and RGSNP10 are the two best-selling guns I ship, and it is not close. The 90 tracks through coral heads and bommies without catching. The 100 gives you a bit more reach for open reef edges. Both are easy to load, easy to handle, easy to live with.

Do not buy a Tuna for this work. You will get the fish, but you will also be blowing holes in reef structure behind every shot and fighting a longer, heavier gun through tight terrain.

Use case two: mixed, Phuket and Andaman shore work

Target species: reef fish plus the odd pelagic chasing bait along a headland. Visibility 8 to 15 metres on good days. Shot distances up to 5 metres.

Pick: Snapper 110 or Tuna 100. This is the overlap zone. If you lean reef, the RGSNP11 handles 90 percent of what you see. If you lean pelagic and have the technique to load a 16mm, step to the RGTUN10. You will give up a bit of manoeuvrability for real stopping power on anything with shoulders.

Not sure which side of the line you sit on? Try the speargun selector tool. It asks four questions and gives you a spec.

Use case three: bluewater, drop offs, Similan-adjacent

Target species: Spanish mackerel, dogtooth tuna, wahoo, big GTs. Drift dives. 15 metre plus visibility. Shot distance 4 to 7 metres.

Pick: Tuna 110, 120, or 130. This is what the Tuna line exists for. The RGTUN11 is the sweet spot for most Thai bluewater, enough length to reach out without becoming a chore. The RGTUN12 and RGTUN13 belong in the hands of experienced spearos doing proper blue water aspetto and agachon work, often with a reel or breakaway setup.

For serious bluewater shoppers, also look at the bluewater category for carbon rollers and float line kits. That is a different conversation covered in another post.

What people get wrong

”Bigger is always better”

It is not. A 120 Tuna in 6 metres of visibility with surge is a gun that will hit you in the face when the rubber goes slack on a tight swim. Gun length should roughly match the visibility you actually dive in, not the visibility you wish you dived in.

”I will buy the Tuna now so I never need to upgrade”

Maybe. But most spearos who buy a Tuna 120 as a first gun end up buying a Snapper 90 within the year for reef work anyway. If your budget stretches to one gun, buy for the conditions you dive most, not the conditions you dive twice a year.

”Rob Allen is overpriced in Thailand”

Thai retail on Rob Allen runs about 40 percent over Durban wholesale because of shipping, 10 percent import duty, and 7 percent VAT on CIF plus duty. That is the honest math. What you get for that markup is a gun that is actually in Thailand, a lifetime warranty that actually works because I am on the Rob Allen dealer locator, and 3-day delivery. Full breakdown on pricing here.

My personal picks, for what it is worth

For 8 years of Thai diving, my primary has been a Snapper 100 rigged with a reel for close reef work and a Tuna 110 for anything pelagic. I have shot more fish with the Snapper 100 than every other gun combined. It is not glamorous. It is just right for the water here most of the time.

If you are starting from zero and dive mostly the Gulf side, buy a Snapper 90 or 100, learn to load it properly, and spend the rest of your budget on a good mask, good fins, and time in the water.

The straight recommendation

• First gun, reef focused, Gulf side: RGSNP09 or RGSNP10
• First gun, mixed Andaman shore work: RGSNP11 or RGTUN10
• Upgrading for bluewater and pelagics: RGTUN11 or RGTUN12
• Dedicated dogtooth and wahoo hunting: RGTUN13, and consider the GT Carbon line

All of these are in stock or on the next order. See current speargun inventory.

Questions on your specific water and skill level? WhatsApp me directly. +66 (0) 80 535 2528. I will give you an honest answer, including the one where I tell you not to buy the bigger gun.