A friend with an 1160 recently asked for some advice on how to prepare to take his boat offshore. Some of my answers might interest others.
A big topic. I am sure there are many others more expert than me. But here goes, in the spirit 'free association'.
A nightmare I have not experienced, but fear, is of being in a squall at night with coral reefs downwind in the dark and to have the anchor drag. In the Pacific anchorages are often significantly deeper than we are used to using in Australia. Anchor too close in and you risk getting your chain round a bommie. Anchor further out and you might have insufficient scope. I inherited 55m of Chinese chain which rusted. I replaced it with 66m of PWB chain, to which I spliced 60m of nylon rope. I replaced the CQR anchor with a Rocna. The old CQR got promoted to be my kedge, replacing the smaller CQR.
We carry a Powerdive 12v compressor which allows me to dive to 8 metres to see what is happening.
I have ordered a Trident OpenROV underwater drone which I will use to check my anchor, or do reconnaissance if the anchor gets caught.
We have enjoyed the independence which comes with water self-sufficiency. Many islands are short of water. Many sources of water are dodgy. Fetching and carrying jerrycans by dinghy from a possibly infected stream is an adventure I am happy to forgo. Ours is a Spectra Ventura 200T MPC It uses about 8 amps and makes about 30 litres an hour. The backflush at the end of a job is wasted, so there is an advantage in using it for several hours at a time, (involving one backflush) rather than many short sessions (involving several backflushes.) We got the version with several bells and whistles, which I have never regretted. It does its maintenance remotely. The T stands for Tropical, or >10°C temp seawater. This was a restriction that George was delighted with, but if you ever planned to go to colder climes you might want the 150 model, not the T version.
I love it. I can see ships easily. I can read their MMSI. I can call them up. They can see me. Much better than a bit of metal origami up on the spreader and fingers crossed some bored crew member remembers to look at the radar. We also have personal AIS units on our life-jacket harnesses. If George falls in, she pops up on my chartplotter and makes it much more likely I can find her again.
Another plausible nightmare, more likely when in the third world, is to take on board some dodgy diesel fuel. That can seriously spoil your whole day, especially if you put it in both tanks. :(
A friend of mine, who is a pilot, kindly gave me a Mr Funnel filter. We religiously put all incoming fuel through it. We also add a fuel additive to reduce the chance of infection, which we had once. http://www.fueldoctors.com/ There may be a better one.
You will probably have read of Royce’s adventures with Nimrod’s steering system. We have rebuilt it with duplicate cars on the track under the BBQ. The new Seawind 1160 Lites have a different design. Enough people have had trouble with the original, that I would do a pre-emptive reconstruction before going offshore.
Once you go off-grid, especially if you want to leave the boat somewhere without shore power, the balance of amp inputs to outputs becomes critical. The history of our ownership of Nimrod is the story of trying to increase inputs and decrease outputs.
This is an ongoing story. Some thoughts:
Tighten your alternator belts.
Ensure you have an MPPT solar regulator, not PWM or earlier. http://www.enerdrive.com.au/mppt-vs-pwm-solar-controllers/
Consider lithium batteries when your batteries need replacing.
Increase your solar panels. My slim zip-to-the-canvas sunshade ones are deteriorating after 3 years.
Eliminate greedy consumers. Have LED lights. We changed our TV to a LED version and saved about 30 amp hours a night.
We have a Fischer Panda diesel generator. I would consider some ability to enhance your generating capacity somehow. Genset. Honda generator. Bigger alternators. Wind generator. A lot of the ARC boats we saw in Vava'u had WattandSea hydrogenerators. http://www.wattandsea.com/en/cruising-hydrogenerator. I guess they increase in usefulness the more you are on the move.
On the way to PNG ours ripped with pounding into the sea. I replaced them with Spectra ones using braid cord. They ripped again on the way to Tonga. I have replaced the cord with Spectra, and obsessed over tensioning it. It has yet to be tested again.
We added a No 2 Genoa and have hardly used anything else since.
I think the standard jib is too small.
I do think one needs the ability to access GRIB files when out of range of 3G or VHF. We have an Isatphone Pro linked to the laptop. SMS is free, land to us, and cheap, us to the world. The field has moved on since I researched it. PredictWind has an arrangement with Iridium I would check out. https://www.predictwind.com/iridium-go/
Things to economize on?
I'm skeptical about the radar. It's helpful to spot errors on the chart. But ours is really a bit of a toy when it comes to spotting small things like yachts. Anything big enough to carry AIS is much more easily seen with that. Icebergs don't have AIS. George keeps me away from them!
I'm also dubious about the life raft. One of the more probable disaster scenarios is to hit a reef. If you hit a reef on the windward side it doesn't appeal to me to launch a blow up paddling pool. Better set up your RIB with survival options. We have a raft because it was requirement to join the Louisiades Rally (which didn't happen).
Air con was on our boat when we bought it. It's use is largely restricted to hot marinas with shore power.
Some people believe in HF radio. Expensive to buy. I think it's dying.