Open Water Swimming Tasmania
DISTANCE
34km
WATER TYPE
River
EXPERIENCE
Advanced
LOCATION
Hobart
REGION
Hobart & South
Swim Stats
Route: New Norfolk to Tasman Bridge
First completed: January 1975 (Des Renford, Australia)
Successful swims: 168 (as at 30 April 2026)
Fastest male: 5:35:21 (Andy Donaldson, March 2022)
Fastest female: 5:49:37 (Josie Page, December 2025)
Earliest swim: 4 December (2025, 7:34:46 - Martin Law & Chad Edward-Smith, Tandem)
Latest swim: 10 May (2025, 8:20:00 - Veronique Wong Kai In)
Route: Tasman Bridge to New Norfolk
First completed: January 2022 (Brenda Norman, Australia)
Successful swims: 2
Fastest male: -
Fastest female: 9:26:00 (Brenda Norman, January 2022)
Route: 2-Way - Tasman Bridge to New Norfolk Return
First completed: January 2022 (Brenda Norman, Australia)
Successful swims: 2
Fastest male: -
Fastest female: 18:59:00 (Anna Strachan, February 2022)
See the Derwent River Big Swim site for the Honour Roll for the one-way New Norfolk to Tasman swims.
Overview
The Derwent River Big Swim (DRBS) is Tasmania's original, iconic marathon swim and forms part of the Australian Triple Crown of marathon swimming.
The swim's official distance is 34km although it more usually measures 35km. It starts in the freshwater of the Derwent Valley and reaches salt water roughly at the halfway mark at Bridgewater. The second half takes the swimmer past tourist attractions and maritime industry with Kunanyi / Mount Wellington as the backdrop.
This swim is managed by the Derwent River Big Swim Association. For more information and for all enquiries and bookings, visit their website at www.derwentriverbigswim.com.
Route Description
New Norfolk to Tasman Bridge
The swim starts under the Blair St Bridge in New Norfolk and the first 8 kilometres pass through the scenic Derwent Valley. Depending on the tide times, this section is unfortunately often done in darkness so, while you might not get to see the beautiful scenery, the water is typically calm.
The river widens over the next 7 kilometres past Murphys Flat Conservation Area as you head down to the bridge at Bridgewater, which is roughly the halfway point of the swim. While an incoming tide does push upstream of Bridgewater, it will be counteracted by the downstream flow of the river. Once at Bridgewater the tide comes into effect more. Here you'll notice that the water becomes saltier.
A further seven kilometres on you'll round Dogshear Point - more commonly known as Cadbury Point after the nearby factory - before continuing on to the third bridge: the Bowen Bridge.
From here, you can clearly see the finish point but it's still another six kilometres downstream, past Hobart's industrial zone. The swim finishes as you cross under the Tasman Bridge.
Tasman Bridge to New Norfolk
This original swim but done in reverse! You will typically start at the Tasman Bridge on an incoming tide to get the maximum push up the river. Once past Bridgewater, though, it's a long push against the natural flow of the river. This swim has only been completed twice (except as part of a two-way). Good luck!!
Tasman Bridge to New Norfolk Return
The two-way Derwent River Big Swim will again typically start at the Tasman Bridge on an incoming tide. The first leg is completed when the swimmer passes underneath the Blair St Bridge in New Norfolk, before turning to start the 'easier' leg, using the river and outgoing tide to assist. This swim has only been completed twice.
See map below or click here to view in Maps.
What you should know
The most popular months for the swim are December to March. Depending on how warm Hobart's spring temperatures have been, expect water temperatures of around 13-14C in early December, rising to 15C by the end of the month. Water temperatures in January to March are around 16-18C.
The water upstream of Bridgewater is usually warmer, often 19-20C during the peak summer months.
The water temperature starts to drop off from early April and will be under 15C by the end of month. The latest swim to date was on 10 May, with water around 13C.
The swim is usually timed to arrive at Bridgewater around high tide, to take advantage of the outgoing tide for the second half of the swim. It's not unusual to have speeds of 4-5kmh during the later stages of the swim.
Prevailing winds are north-west which provide a favourable push to Bridgewater (a nor-easter makes the section along Murphys Flat a bit tougher).
Winds often swing round during the morning to be from the southeast or southwest, picking up in the afternoon. For this reason, swims often start in the dark in order to be finished by noon.
Before you go
All Derwent River Big Swims are completed under the auspices of the Derwent River Big Swim Association. Choose your pilot, organise your swim window directly with your pilot, and then register your swim at www.derwentriverbigswim.com.
Pilot boats will typically meet you at the pontoon outside the rowing club on the Esplanade, New Norfolk. There is then just a short boat ride upstream to the start at the Blair St Bridge.
Once you've finished your swim, pilots will drop you at one of the boat ramps or marinas near town (e.g. Rosny boat ramp, Prince of Wales marina, Regatta Grounds).
Make sure you have worked out how you are going to get to the start or from the finish. The pilots are not responsible for taking swimmers/crew back to New Norfolk to pick up cars.
Honour Roll
Swim # | Name | Date | Time | Country | Route | Category | Type | Notes | Ratified By |
|---|---|---|---|---|---|---|---|---|---|
1 | Brenda Norman | 19/01/2022 | 9:26:00 | Australia | Tasman- New Norfolk | Unassisted | Solo | First recorded swim | DRBS |
2 | Brianna Thompson | 30/01/2022 | 11:43:32 | Australia | Tasman- New Norfolk | Unassisted | Solo | DRBS | |
3 | Brenda Norman | 30/01/2022 | 19:51:00 | Australia | Tasman- New Norfolk- Tasman | Unassisted | Solo | First recorded 2-way | DRBS |
4 | Anna Strachan | 12/02/2022 | 18:59:00 | Australia | Tasman- New Norfolk- Tasman | Unassisted | Solo | First recorded 'reverse' swim | DRBS |