Grady White Canyon 306 Hull Truth

SkipperSam

Shopping the Canyon 306 and I’m allergic to brochure verbs. I want the hull truth… as in the stuff you only admit after you’ve sold it to your brother-in-law. SeaV2 sounds cool, but does it stand for “Sometimes Eats 2 vertebrae” or “Seriously Excellent x 2”? Help me calibrate expectations before I trade money for fiberglass.

Looking for real-world, warts-and-all intel from actual 306 owners and ex-owners. Not “rides like a 40” on a glassy Tuesday morning with a tailwind and one labrador aboard. I want the ugly, the fixable, and the hacks that make it shine.

Ride in honest slop: With 2-3 ft tight bay chop, where does the 306 actually like to run without tenderizing your kidneys? 18-22 kts with tab and trim? Or is it a 26-30 kts or nothing kind of hull?
Wetness factor: Quartering wind and quartering sea-do the reverse chines keep life dry, or are the aft corners baptizing the cockpit? Anyone added spray rails or wedges that actually worked?
Following sea manners: Any bow-steer or “I, for one, welcome our new following sea overlords” moments? Tab/trim playbook to keep it from stuffing?
Drift/anchor behavior: Snap roll drama while chunking or kiting? Better or worse than other 30-foot CC deep-ish Vs?
Scuppers and deck height: With two adults aft, ¾ fuel, a cooler of ice, and the typical tackle hoard, do the scuppers burp your ankles or remain above the wet line like civilized scuppers should?
Real deadrise reality: The transom number is what, truly? Owners who’ve run Regulators/Everglades/SeaVee in the same size-how does the 306’s variable deadrise translate to “butt dyno” softness?
Engine setup that actually works: Engine height, prop pitch, and tab routine for twin F300s or F250s. Anyone running OFX/Rev4/Enertia/PowerTech combos that made the boat wake up? RPM vs mph vs gph data welcome. Slip numbers if you’re extra nerdy.
Repower truths: Any transom cracks, bracket drama, or deck flex after stepping up to F300s/F350s? If the bracket’s Armstrong, any corrosion gotchas or weep holes to monitor?
Weight placement hacks: Moving batteries forward? Keeping the forward fishbox wet to tame the hobbyhorse? “300 lbs forward fixed my marriage” stories encouraged.
Bilge/fishbox plumbing: Do the boxes actually drain overboard, or do they perfume the bilge like eau de mahi on day three? Any common clog/leak points or easy reroutes?
Hull slap at rest: Is it a ninja at anchor or does it practice free-form percussion on a light chop?
Fuel burn honesty check: 28-32 kts cruise numbers with realistic load and hull growth. No “just waxed and no T-top canvas” miracle runs.
Seakeeper 1 installs: Anyone done it? Where’d you stuff it, how much performance did it cost, and did it tame the roll enough to justify the new electrical religion?
Longevity gremlins: Deck coring moisture hotspots, soft spots around hatches, console base cracks, gel crazing at the bracket knees-where should I poke before my wallet cries?
Photo evidence: Loaded waterline pics. I want to see where she actually sits when you’re fueled, iced, and optimism-packed.

Bonus points if someone strapped an accelerometer or used a phone app to record peak heave/impact forces at various speeds in 2-3 ft chop. I will 100% nerd out over CSVs, then pretend I bought on “feel.”

Bottom line: If you were setting up a Canyon 306 today to be the least poundy, least soggy, most predictable 30’ CC, what exact recipe would you run? Props, engine height holes, tab baseline, weight distribution, anti-spray tweaks-the whole voodoo. If the answer is “buy something else,” name it and say why, with the ride/fish/tradeoffs spelled out.

Spare me the marketing poetry. Give me the hull truth.

CruiseControl

Short version from a glutton-for-punishment who’s put a lot of hours on 306s and wrenched a few:

Slop sweet spot: It’s a two-gear hull. 17-19 kts with 25-35% tab for comfort, or 26-29 kts with just a hair of tab and neutral-to-slightly-in engines. 21-24 is the dental-work zone.
Wetness: Quartering wind will baptize the aft quarters. Reverse chines help head-on, not on the rear shoulders. Biggest fixes I’ve seen: raise motors 2 holes, 4-blade props with more rake, and add SmartRail S90 (run ₇-9 ft starting ahead of the shoulder). Clears a surprising amount of mist. Wing curtains if you care about crew morale.
Following sea: Tabs up. Engines 2-3 bars out. Keep speed 1.2-1.4x wave speed and steer off the quarter. Any bow-steer you’re seeing is usually too much tab or too much forward weight.
Drift/anchor: Rolls less than a 24° constant-V (Reg 28/30), more than a beamy bay boat. Some shoulder slap at anchor in a quartering ripple-snubber, bow 10-15° into it, or a small drift sock fixes the percussion set.
Scuppers: With ¾ fuel, two adults aft, cooler: expect a burp. TH Marine ball scuppers + fresh gaskets help. Moving batteries to the console fixes it for good.
Real deadrise: _20° at the transom, sharp entry. Softer than your brain tells you at the bow, not “Regulator soft” overall. The trade is friendlier following-sea manners and better stability at rest.
Props/height that work: F300s like engines 2 holes up with either Rev 4 17P or Enertia Eco 19P.
- 4300 rpm: ₂₈-30 kts, ₂₂-24 gph total (1.2-1.35 mpg)
- 4700 rpm: ₃₂-34 kts, ₂₇-30 gph total (1.1-1.2 mpg)
- WOT 5600-5800: high 40s, call it 0.9-1.0 mpg
Repower reality: It’s a molded “Grady Drive,” not an Armstrong. No aluminum corrosion drama, but inspect for gel crazing at the knees, bedding at the flange, and backing plates. I’ve seen stress cracks at the inner corners from guys over-tabbing.
Weight hacks: 150-250 lb forward calms the hobbyhorse. Batteries to the console are the cleanest move; a little chain or a few gallons in the forward box works but don’t go crazy or you’ll pay in a following sea.
Boxes/bilge: Fishboxes go to macerators overboard; saggy corrugated hose is the stink culprit. Reroute with smooth-wall, add proper anti-siphon loops, or convert to diaphragm pumps. Check livewell seacock fittings for weeps that perfume the bilge.
Seakeeper 1: Works, but put it under the console if you can-aft installs cost you scupper freeboard and pitch response. Expect ₄₀-50% roll reduction at drift, -0.1 to -0.15 mpg, and about -1 kt.
Longevity checks: Console base and T-top feet for spider cracks, hatch cores around hinges/latches, fuel tank coffin lid for leaks (water intrusion), and the bracket knee area for hairlines. Nothing exotic, just common sense on a used 30.

If headsea plush is your north star, a Reg 28/30 or SeaVee 29/32 is softer at 22-26 kts-but they’ll roll more on the hook and live lower at the scuppers. The 306’s party trick is being predictable and sane in a following sea.

My “least poundy, least soggy” recipe:

Engines 2 holes up
Rev 4 17P or Enertia Eco 19P
Bennett tab baseline ₂₅-30% in head chop; tabs up in following
SmartRail S90 along the forward shoulders
Batteries in the console; 150-200 lb forward total
TH ball scuppers; smooth-wall drains with proper loops; diaphragm fishbox pumps
Helm wings for quartering wind days

It’s not magic-carpet soft, but set up like that it stops trying to beat you up or soak you every time the wind clocks around.

DriftwoodDale

Couple of add-ons that haven’t been hit yet, learned the hard way:

Low-speed headsea comfort: If you want a true 16-18 kt “second gear,” Permatrims on the twins plus slightly larger tabs (or Bennett drop-fins) help you hold plane without burying the bow. That takes the sting out of the 2-3’ tight stuff when 22-24 is miserable.
Spray control nuance: SmartRails work, but placement makes or breaks it. Start them ₁₂-18″ aft of the stem and end them just forward of max beam. If you run them into the aft shoulders you’ll kick mist back aboard. A short wedge behind the rub rail at the rear quarter cleans up the last bit.
Motor height sanity check: AV plates should be 1-1.5″ above the keel line at speed. If they’re dragging water when trimmed neutral, you’ll get extra spray and a harsher ride. Two holes up is usually right, but judge by the rooster tail (should be knee-high and tight).
Prop note you can bank on: If you’re on Yamaha SWS II 17P and the boat feels bow-heavy, try Enertia Eco 18-19P. You’ll give up a tick of WOT but gain lift and midrange mpg. PowerTech OFX4 can lift too, but it’s easier to over-rev light.
Following sea predictability: Any “grabby” feel with no tab and modest engine trim is usually forward CG. Move mass aft a touch or pull 30-50 lb out of the bow locker. Tiny changes matter on this hull.
Drift fixes that actually work: A small drift sock off the bow quarter beats chasing the wheel. It kills the snap roll and the foredeck slap without needing a gyro.
Scupper reality: Measure static freeboard at the scupper lip with your typical load. If it’s under ₁.5″, you’re going to get burps. TH ball scuppers plus moving the house/start batteries into the console fixes it permanently.
Fishbox/bilge stink cure: Ditch the macerators for Whale Gulpers, run smooth-bore hose with a high loop and proper vents. The corrugated hose is the smell factory, not the boxes.
Build-year watchouts: Early 300-series had more spidering around the console base/T-top feet. Also look for hairlines at the inside bracket knees and the fuel coffin lid bedding-both are common, not catastrophic, but leverage for pricing.
If ride-first is the priority: Reg 28/30 is softer at 20-24 but you’ll live with more roll and wetter ankles. SeaVee 290/32 rides great but likes to run faster to be happy. The 306 sits in the middle-predictable, a little firm unless you set it up to cheat the low-speed planing.

If I were setting one up tomorrow: two holes up, Enertia Eco 18-19P, drop-fin tabs, Permatrims, SmartRails ending before max beam, batteries in the console, Gulpers, and a small drift sock in the bag. That recipe makes the boat a lot less poundy and a lot less soggy without turning it into something it isn’t.