Snow Petrel..The boring details

Snow petrel

I bought Snow Petrel (then named Obsession) with the plan in mind to sail to Norway and Spitsbergen via cape horn, and maybe then to Antarctica. She was always envisioned as an intermediate boat and not the perfect boat.

Before Snow petrel I had lived aboard my 26 foot Warsash One Design "Reiger" for 5 years, and had sailed her across the Tasman sea from NZ singlehanded. My choices were to upgrade her for further offshore work or to get a new boat.
A proud new owner with alot of work to do..
It was a hard choice, I was really fond of Reiger, she was similar to a folkboat and very beautiful to look at and sail, and over the years had put a lot of work into making her a safer offshore boat with a bulletproof rig, sails and a small strong cockpit. She had been sailed to NZ from England by Jim Dilly, and it would have been nice to continue on her world trip... Also she had been my home since I was 21. I remember sailing her through the cook straight tide rips, lee decks under in a squall, no engine to get me out of trouble, she was a true friend and to sell her seemed like a betrayal.
Reiger in Tasmania. Photo Greg Hockey

Cape horn, southern ocean and ice, 26 foot fiberglass boats aren't recommended, its possible (Jarle in his little Berserk) but I'm not that brave ! so cold logic won and in consultation with my girlfriend a wish list of features was drawn up.

At least some full headroom for living aboard
More room for stores and living aboard, at least 28-34 foot
Metal (steel or alloy) for ice and peace of mind at sea.
Good spray dodger for shelter
Good Galley and an offshore layout
Under $40,000  I wanted to go soon not in some distant future. simple economics!
Workboat finish. I prefer to spend time and money on improvements not cosmetics
An inboard diesel for ice work. Reigers 3.5 hp outboard and sculling oar would not cut it.
A simple rig that one novice sailor could easily handle , So I can sleep while crew are on watch.
an interior that's easily unscrewed to make changes and inspect the hull
Tiller steered for simplicity and to help a windvane work better (less friction)

The search begins..

Obsession was a fairly standard Roberts 34 (the older design not the more modern Roberts 345) Overweight at 8 tonnes and under rigged with only 490 or so square foot of sail, but was  honestly built with a solid and simple quality that appealed to me. She had been offshore 3 times, had alot of gear and was at the right price.

I bought her,

Refit nearly finished..
And then spent three years refitting her, and paying her off. At the time I was working at the maritime college in northern Tasmania and it was hard living aboard, saving money and trying to get some work done on the boat, too hard for my fiance, She left. and the dream was Shattered. The Commonwealth bay trip was a part of a rebuilding from the fragments that were left and were financially possible. All dreams have a cost, and its not necessarily in paid for in dollars.

Work done on Snow Petrel to improve her:
  1. Cut of all deck fittings except the Samson posts. weld up all holes in deck
  2. weld on new SS fittings including stanchions, handrails bow rollers and Tabernacle
  3. re insulate with polystyrene.
  4. weld in all windows and cut out smaller ones (mostly for looks but also safety)
  5. improve interior by painting and wood trim
  6. sandblast deck and repaint
  7. repaint hull
  8. new cockpit drains above waterline
  9. Hard dodger
  10. mount self steering
  11. remove mast and check + paint
  12. re rig with galvanised 7x7 wire
  13. new roller furler unit
  14. remove aft tankage, to heavy for stern
  15. new boom
  16. new hatches+ extra hatch over saloon
  17. diesel heater
  18. extra stringers
  19. watertight bulkheads forward
  20. remount engine and new shaft
  21. SSB radio
  22. + one million other "little" jobs

This took about three years of procrastination  and sporadic bursts of short lived enthusiasm. There was some pretty depressing times where Snow Petrel looked more likely bound for scrap metal than the southern ocean. Friends of mine have built whole boats in that time, and maybe it would have been better to have started from scratch, but all the while I managed to live aboard and this helped to pay her off quicker. I don't recommend this approach, its much better to inherit a fortune and buy the boat of your dreams. I would still like to build the next boat from scratch one day...
Details of snow petrel

Roberts 34 multichine steel. Long fin keel, Skeg hung rudder.
Sloop rig.

LOA 10.15m (33'6")
Beam 3.2m (10'6")
Draft 1.9 (6'2")
Displacement 8 tonnes approx when light
Ballast 2.5 to 3 tonnes lead


Hull and decks 3.2mm steel
backbone10x75mm ,
Stringers and chine bars 6x25 mm approx 1/2 meter spacing
Deck beams 6x50mm approx 1 meter spacing
Keel structure is incorporated into a keel diesel tank making a very strong structure
All tanks are welded integral 3.2mm steel making a very strong midships section.  
The Rudder was reinforced with an extra 6x50mm floor to help distribute loads into the chine.
Frames have largely been cut away except around the chainplates and midships
All the Bulkheads are bolted plywood and contribute to the stiffness of the structure.

Rustproofing and paint systems

All paint is epoxy, mostly Jotun and Wattle. lots of rust had formed on deck behind and under fittings. after removing the Genoa track there were several holes found in the deck. behind and under each stanchion was a real rust and dirt trap.

All fittings were cut off and new stainless fittings welded on rather than bolted on  to reduce future leaks and rust. Care was taken that all fittings would be easily painted around and accessible by a sandblaster or hand tools.
All pipe was first welded to stainless plate before welding to the deck to reduce the chance of rust inside the welds

Stainless steel chain links were welded to the deck for sheet lead blocks and padeyes

Hatch coamings were welded up stainless steel and welded directly to the deck.

Chainplates were cut off and new Mild steel chainplates welded on with stainless steel inserts and edging.

After all the work the decks were completely sandblasted and the sprayed with epoxy. Then I faired and filleted the deck with epoxy filler to stop most of the water pooling and built up 7 layers of rolled on epoxy. A topcoat of two pack polyurethane protects the epoxy. A water based rubbery non skid gives a good non stick but isn't very tough.

Inside the boat the original epoxy was in good condition needing only minor touch ups with phosphoric acid and then epoxy. occasionally I have used a dab of rust converter (tannic acid based?).
Time will tell how the treatment lasts without sandblasting.

Since sandblasting the decks I have had no rust other than on chipped or worn areas in four years or so. All stainless is left as is, no polishing or other time wasting spent on it. Maybe one day I'll consider it worth doing. 

The topsides are red 2 pack polyurethane over epoxy bog and old but firm oil based paint. lots of flattening powder and a coarse roller hides the worst of the welding distortion.

Underwater is two coats of epoxy tieing all the old antifouling together with micron CSC self polishing antifouling over it. Occasionally I will lose some epoxy and go back to older antifouling but almost never back to steel. I may One day blast the hull back to steel but no real need to yet. 

6 big anodes protect the hull and one for the propshaft.
they hardly seem to do any work.


The Old nasty fiberglass insulation was removed and replaced with 45mm polystyrene cut to fit tightly into all spaces between frames and stringers. Any chinks have been filled with polyester batts. Thin Plywood lining protects the polystyrene.

Polystyrene has only two virtues, its cheap and it insulates well. Ideally I would sprayfoam the boat. or at least use a better quality of foam. I still find polystyrene beads around the boat!

She is very easy to keep warm and condensation free. But I do worry about water and rust under the foam and also mould forming . Nether seems to be a problem so far.

For the ice we cut foil lined bubblewrap inserts for the windows and had twin wall clear polycarbonate sheets to double glaze all the hatches. These were not needed.

thin camping mat was also glued to the inside exposed aluminium hatches.Curtains closed off the forward cabin and also the storage berth to reduce the heated area.

We could normally keep the main cabin above freezing with out the heater, but the floor was very very cold, I plan to insulate the floor with cork tiles, And also cover the exposed integral water tanks in the main saloon. At head height it was often 10-15 degrees warmer than at floor level.


Two dorade boxes ventilate the main cabin as does the flue for the heater. I really try to let the steam from cooking escape whenever possible by leaving open the main hatch while cooking, even in Antarctica, otherwise the boat can quickly become very damp. The hard dodger with a closing flap at the back helps by stopping all the warmth from rushing out with the steam, forming a partial air lock. Condensation forms in the dodger where it can do no harm.

In the Katabatic winds Jon and Mat closed of the dorades above them with socks, to stop the blast of cold air over their bunks. I made sure they were clear before cooking or running the heater.

We could cap the dorades from the outside for extreme weather, but never did. I think a squirt came down on dads bunk in the knockdown. Serves him right for being so cheerful.  A Swedish vent system with a extra water trap into the bilge is ideal. 

Good seagoing ventilation is essential. without it the boat can get incredibly damp inside, dampness leads to mould and then everybody gets chest infections or worse!


A LPG three burner gimbaled stove with an oven. We used the pressure cooker alot. We carried two nine kilo bottles and a 4.5 kilo bottle of gas. The bottle in use was kept below and turned off after use. Not an ideal system,(not at all recomended, gas is dangerous and if I explode I have only myself to blame..) but I also don't like complex systems with big pipe runs through the boat. We had lots of gas left over. The Diesel cabin heater could also have been used if needed.
A MSR XKG Diesel burning expedition stove was onboard as a backup, and for survival use.

Through hull fittings

Only 50mm sink outlet and 25mm salt water intake for the galley. All the rest welded up, including log and toilet fittings. Depth sounder transducer was fitted with a guard to protect it from ice.
Cockpit drains fitted above the waterline.

All through hulls 316 Stainless Steel with stainless steel ball valves as a lesser of many evils compromise. No electrolysis or crevasse corrosion... yet...


Thetford Portapotti chemical toilet (no chemicals used however) 16ltr holding capacity. basically a posh bucket and chucket. Advantages; no seacocks, not much to go wrong. and can be emptied away from the boat for environmental reasons. Downside; it has to be emptied daily with three people. It never froze,


An old Taylor's diesel drip feed heater I bought second hand for $100. A larger SS top was made so as to fit a pot. My chimney top was lost during the knockdown so a tin can did instead.

It used about 0.2 ltrs of diesel/hour at its lowest setting or 5 ltrs per day. Far to much to run for more than a couple of hours a day. In reality we only ran it as a treat or to dry clothes. Other sources of heat was the engine (which also provided electricity) and cooking (lots of moisture). Our most reliable heating was warm clothes, food and hot water bottles.

Diesel 280ltrs in keel tank + 50 litres in Jerry cans
I Added heating oil to the diesel to reduce waxing problems. This may not be Ideal for the engine but neither is filters plugged by wax. Winter grade diesel would be better but was not available in time. the Keel tank I expected not to get below -1 degree ( water temp) so I added less heating oil. The jerrys were more like 50/50 to give a CFPP of -8 degrees.
we had no waxing problems.

The main engine uses about 3 litres/hour at 5.5 knots (flat water) so we had about 4 1/2 days or 605 NM but it was quite possible we could have 2 days of ice navigation in and then another 2 days out using up most of our fuel. As it turned out we probably had 130 litres left when we got home. A good safety margin, but it could have easily have been used in the pack, prolonged calms, or after a dismasting.

I expected to have a big high pressure sit over us near Tassie, and thought it would be nice to use any left-over diesel to keep moving, nothing worse than 150 miles to go, no wind and only reserve diesel left. As it turned out we had reasonable winds for the last half of the trip home. And so we got home with lots of fuel left (to my rushed crews annoyance I'm sure..)

Waiting for wind ...
I normally won't motor on a long passage until the sails start to slat regularly, and personally am quite happy drifting with the sails down for days in calms (as long as i still have some books to read!). For some reason this attitude tends to quickly send crew into a high state of agitation. rush rush rush....


Approximately 300 liters. we converted the starboard water tank (under mats bunk) into food storage and had 150 litres in the port tank + 150 litres in 2 litre bottles and jerrycans.
the main tank and all water pipes froze solid, but as planned the 2 litre bottles were easily kept liquid.

We topped up the tanks from a frozen lake at Cape Denison. had we been more on the ball we could have topped up before the katabatics when there was running melt water at sea level. I made sure there was a air gap when it froze up. As the tank unfroze on our way north we had ice banging about in the tank for a couple of days. If it wasn't 3mm steel I might have been worried about it. I was glad it wasn't under my bunk !

We used salt water for all dishes and much cooking and returned with at least 150 litres of water, and maybe much more.


Some awful huge hydraulic gearbox, looks like a Chinese PRM copy. Isoflex flexible coupling to act as a drive saver, Conventional stuffing box with a lip seal added to stop drips. this is only partially successful but no space for a ceramic face seal. Fixed 3 bladed bronze prop. Shaft lock is a bit of wood jambed in the coupling. Split coupling because no space to get a normal tapered coupling nut on or off.

The `reputable` precision engineering company that did  the machining must have had a bad day because not only did they not get the bits finished in time, but after spending au $2000 on all the bits not much actually fitted together (the prop wouldn't even fit on the new shaft, even though I had left it with them!), but after a couple of stress full hours of angle grinder re-engineering it all to fit together.

This debacle put me way behind on schedule and budget, and made me remember why I try to do all the work myself, instead of relying on others.

Izusu 3KR1 industrial 3 cylinder motor, 30 hp or so, keel cooling through the skeg, Dry exhaust. Blue.. with a wee bit of rust. All the bits stuck onto it seem to be made by bosch and work well, are readily available and cheap, Very smooth running. I made sure the antifreeze was new, and had enough onboard for a complete coolant change if needed. I rigged up a backup pickup tube so I could gravity feed some diesel directly from a jerry can into the first filter if needed. 

We remounted the engine and got new propshaft before the trip. I was supplied horrid flexible mounts made of plastic, by the same 'reputable' engineering firm that stuffed up the shafting. I had no time to send them back and get proper ones. Some guy at the engine mount company tried to tell me they are stronger than steel but I don't like them one bit. At least the engine won't go through the 3mm steel cockpit floor when they let go in a rollover. I will put some safety straps around them someday, to stop them bending the shaft when they break.

The dry exhaust was always plugged and taped up when not in use at sea to stop any chance of water getting into the engine. This (and our crude shaftlock) helps to slow those Impatient itchy engine key turners, conserving fuel.

The dry exhaust is simple, but can get very hot. I have all sorts of clever ideas to cool it with a water jacket, but haven't got round to it yet. I would love to be able to store some of the engines waste heat in the water and fuel tanks for later use. Maybe on the next boat...

This engine and prop combination gives me some maneuverability in flat water in up to 50-60 knot winds.


An inboard skeg hung rudder. Located just behind the propeller so it has no aperture to reduce its efficiency, but still gets the full propwash for instant maneuverability. The skeg is full length and has a long and strong attachment to the hull, at least 1 foot wide at the top tapering to about 4 inches at the bottom. the heel fitting is welded on, so removing the rudder would be a big job, but at least there are no bolts to come undone at sea (as I've had happen since).

The skeg is used as a cooling tank for the engine, so it's filled with distilled water and Glycol, Hopefully preventing corrosion inside the skeg. If the boat was iced in overwinter the heat from the skeg could stop the rudder and prop freezing in and pulling down the stern.

At the back of the rudder I welded on a upside down "v" to enable me to hook in a emergency rope or chain if the tiller or rudderstock broke. Ropes shackled through a hole can then be used as a more permanent repair. A 2 inch ice blade stops ice or flotsam getting trapped between the top of the rudder and the hull. Its not really big enough.

After hearing about problems many steel boats were having with skeg/hull joints I reinforced the hull around the area of the skeg. First I welded 50x6mm flat bar around the inside at the joint, and then notched in a 50x6 flatbar frame tieing the skeg across to the stringer and chine bar. I also added braces to the sternpost (rudder port?). The joint between the steel rudder port and the plastic section going to deck is normally well above the water but at speed it started leaking slightly. It was easily fixed with goop. 


Mostly by the Flemming "Major" windvane which has done a excelent job on Reiger and now Snow Petrel. It steers her through storm and calms and I never have had to hand steer at sea.

I have a variety of vanes made of 6mm plywood, The regular one has big lightening slots and a nylon sock that can be removed to reef it. For long periods of strong winds a tall tapered skinny one is great. in storms a baby one can be fitted. There is no need to change vanes regularly, the big one will do ok in 60 or 70 knots with the sock off. 

I modified the servo rudder by welding on some lugs 1/3 of the way down to take stabilising ropes to turn it into an emergency rudder. 

For motoring or light downwind I have a Autohelm 4000 tillerpilot with a separate control head and fluxgate compass.

If the old flemming were to break a simple sheet to tiller system could be rigged ie by using the storm jib on the inner stay, with a boathook as a sprit boom opposing bungy on the tiller. 

I much prefer vindvane to autopilot, though I note trend toward autopilot only for modern boats. I'm not sure if this is because the boats are too hard for windvane to handle or if its due to a desire for the easy option, ie push a button vs frig around with sail balance and tiller lines. It's often hard to get a windvane to work well on a wheel. A point in favor of smaller boats. or auxiliary rudders.

Over the years I have gotten used to coaxing boats to self steer, and quite enjoy it (or maybe I'm to lazy to hand steer). dad often didn't have the Patience to get the flemming working its best, and I often found him hand steering, maybe he enjoys hand steering?


2x standard lead acid 12v N70Z combined start/house batteries and one extra carried as a separate spare. The batteries were not sealed, So in a rollover some acid would escape, but due to snow petrels range of stability I don't think she'd stay inverted long enough for it to be a problem, Anyway couldn't really afford sealed batteries. They were all combined crank/house, not dedicated deep cycle. This meant any battery could start the main engine even when cold, but also that they won't stand much deep discharging before failure. The fact that I still have the same batteries now shows that it can work out very cost effective so long as they are looked after and your electricity use is low.

Charging systems

1x80 amp bosch alternator with its standard automotive regulator this was mostly used in worst of the blizzard when the solar panels were iced up and it was heavily overcast.

2x40watt solar panels mounted on swiveling brackets on the stern rails. Regulated by an intelligent BP regulator with 3 stage charging and battery monitoring. very impressive! it even equalizes that batteries every month. Got to watch the voltages, it can occasionally push voltages up to 15v in the main system wiring, not good for sensitive electronics. basically the solar panels do all the work and can keep the batteries 80-90% charged most of the time unless I get 2 or 3 days of solid cloud, or am to greedy with the laptop, but my electricity use is very low

backup system was a borrowed ampair tow generator, but this was not needed, even after the failure of one of the old solar panels on the way home due to internal corrosion. (later fixed up and still working).

Electricity demands

Very low, With no fridge or freezer and minimal instruments the main drains were the masthead light at night, HF radio and the laptop. together with the occasional internal light. after the failure of the solar panel we switched of the GPS when not in use.

Navigation lights

I will not use tricolor lights as the red and green filters cut far to much of the visibility. At sea I far prefer an all round white light at the masthead of 25 watts (I now have a LED bulb, MUCH better). This can be seen at a reasonable distance by ships even if it isn't strictly legal. A very bright strobe is also incorporated and is a fantastic ship scarer. I normally only let it flash 5 times to scare away ships, this is sort of legal under rule 34d of the coll regs and it is standard practice on merchant vessels to flash a ship 5 times with the spotlight (signal lamp) if unsure about its intentions. This usually results in the offending ship taking "bold" action to pass well clear.  I have a pulpit mounted bi color light and a stern light for normal waters which are required for motoring anyway. a tricolor is illegal when motoring and also VERY VERY dangerous in harbours and ports where it is far to high to be noticed. I have since used LED bulbs and are very impressed by them.

Radar reflectors and other aids to detection by ships

I normally have two moibri style reflectors permanently mounted at the spreaders and a octahedral that can go on the backstay or flag halyard (where it invariably causes much mischief) for the trip south with a permanent lookout and few ships I decided there windage was more dangerous than there safety advantages, so they were stored below. From experience I am unsure of just how reliably effective they are and prefer my bright all-round white light and red hull. Despite various claims ships do actually keep a much better lookout than most yachts. Unfortunately yachts are very hard to see from the bridge of a ship. Tanbark sails show up better in some cases than white. ideally a mix of colors is good. On Reiger I put a orange head patch on the tanbark mainsail. AIS is looking like a good technology. Active radar reflectors can sometimes be completely masked by modern radar interference rejection circuits. The underwater noise of a big prop can travel along way, and has woken me up in the past (maybe an underwater microphone could be used?). Radar would be useful, but needs alot of skill to use safely. VHF is usually heard by ships but often ignored unless the call is carefully worded to identify the ship precisely. Even then confidence in English speaking by many ships officers means they would prefer to remain anonymous. still worth the call because it makes all ships have a good visual and radar look for you. Beware in traffic of talking to the wrong ship, its possible to set up two collisions this way !


I would have loved to have had a radar, but couldn't afford one. As it turned out we didn't need one, although it would have given us some piece of mind at times. Worst case scenario would have been driving snow, lots of wind and ice about, but in reality it wouldn't show up the really dangerous growlers or small bergy bits, so would have to be aware of a false sense of safety. Would be useful for spotting big bergs to hide behind in this scenario. The real nightmare case would be to have to run off downwind due to extreme conditions in ice waters and finding oneself with a big berg appearing out of the murk just to leeward.. scary and that's where a radar would earn its keep. 24 hour daylight means it's not as needed for inshore stuff as much. The radars extra weight and windage if aft could be dangerous in extreme weather.


GPS, Sounder and mark one eyeball. Anything more will eventually fail, misread and use electricity and money that's better spent on useful stuff. if you can't judge windspeed and boatspeed by eye you should assess whether you should be at sea. Speed logs are a liability by being vulnerable to any impacts. I welded up mine. A compass is always a problem on a steel boat and I chose not to correct it as heeling error and the changing dip angle would quickly make it very unreliable anyway. A masthead Windex and a few bits of tape on the shrouds is a simple reliable means of judging relative wind direction, and the sea reveals the true wind direction and speed.

When I was a kid I remember training for the P class dingy nationals. One of the exercises was to sail with a blindfold on with an instructor watching from a chase boat. amazing how well you could keep the boat in the groove without telltails or Windex.

Being a non engineer I do have engine temp and oil pressure gauges and a voltage meter for the main engine, and would love more sensing on the engine. No doubt a good engineer can sense what the engine is doing without gauges, tuning into slight changes in rhythm, sound and smell,.. You can always wake up an engineer by tweaking the throttle ever so slightly...


Garmen 120 fixed unit visible from the cockpit. and a couple of garmen handhelds as backup. The GPS can be linked to the computer to run as chartplotter. A Davis mk15 sextant, with tables printed off the internet and an old nautical almanac for minutes and corrections, and the concise sight reduction tables. The compass is uncorrected, because I don't think it can be properly corrected for heeling error any way, I check its error regularly against the GPS COG and try to use transits, depth contours and vertical sextant angles around the coast as a backup to the GPS. If all my GPS's die, an unknown compass error would be the least of my worries and easily checked with an azimuth or amplitude, or hand bearing compass from the spreaders (where It still can be effected slightly by the steel hull). We lost use of the compass for the antarctic part of the trip due to our proximity to the south magnetic pole. This caused no real hardship. Satelite sensing compasses (very different from the GPS COG) are coming on the market that could be a boon to steel boats.  It is difficult to use a GPS to steer by in the absense of any external reference due to the lag effect of  COG and SOG readings

To be continued and modified someday... Any comments can be added to this post