Grants Point Cove is a shallow shore dive in the Humbug Point Nature Recreation Area near Binalong Bay, rated 5 out of 10 by the Marine Life Network guide. It offers a sheltered entry and exit when winds run parallel to the coast, with rocky headland fauna in about 4 m of water.

There are picnic facilities at the point, making it a convenient family stop, and snorkellers can enjoy the cove on calm days. The guide warns of large swell 'lifters' - sudden surges that can knock divers off the rocks - so the exit needs care.

It suits new divers and snorkellers looking for an easy shore option close to St Helens.

The north-east coast from St Helens to the Bay of Fires is built of the same orange-lichen granite as Freycinet, and under water it forms rounded boulders, cracks and swim-throughs. The regional guide notes damage from the long-spined black sea urchin (Centrostephanus rodgersii) on several sites; this urchin has spread south with the warming East Australian Current and grazes kelp and weed down to bare 'barrens', so expect patches of bare rock among the weed.

The north-east sees far fewer divers than Bicheno or the Tasman Peninsula. There is no regular charter boat, so most diving is done by Launceston club members and visitors towing their own boats, and conditions are checked on the morning rather than booked in advance. The nearest hyperbaric chamber is the Royal Hobart Hospital, more than three hours' drive away; Launceston General Hospital has no chamber, so evacuation planning and oxygen on board matter here.

From St Helens take Binalong Bay Road north, then the Humbug Point road into the Humbug Point Nature Recreation Area to the Grants Point picnic area (about 15 minutes). Walk over the granite boulders to the cove - a short but awkward carry with scuba gear. Allow about 2 hours' drive from Launceston via Scottsdale or the Tasman Highway through St Marys.

Park close to the water where possible and check the exit before entering; the granite is slippery when wet and swell surges can be deceptive.

The St Helens and Bay of Fires coast faces east and north-east into the Tasman Sea, so easterly and north-easterly swell over about 1.5 m, and the common summer NE sea breeze, make it rough; the Georges Bay bar breaks in easterly swell. Westerly and south-westerly winds blow offshore and give the flattest seas and clearest water. Southerly swell wraps around St Helens Point.

Visibility falls after rain when Georges Bay drains tannin-stained water on the ebb. The cove gives shelter when the wind blows parallel to the coast (north-easterly or southerly), but large swell brings 'lifters' - unexpected surges.

Enter from the boulders into the cove, explore the headland reef at 2-6 m, and return before the tide or swell changes. Watch for surge on the exit. Turn at a third of gas to allow for the swim back and a possibly harder exit, finish with a 3-minute safety stop at about 5 m if the depth allows, and exit where you entered unless an alternative exit has been checked beforehand.

East Coast Scuba Centre (124 Binalong Bay Road, St Helens) is listed by Wikivoyage as offering dive and snorkel equipment hire - current trading status and whether it runs boat dives are unconfirmed. Otherwise sites are dived from private boats and by Launceston clubs and Tasmanian Divers (Launceston) on occasional trips.