Varies between boat hulls a little but in real bad conditions slowing down is the best tactic -

Following sea - trim the motor to lift the bow up so it doesn't dig in - if the boat starts to slewing when going down the face of waves don't power over the top of them -just sit on the back and go at the speed of the wave otherwise you risk flipping.  takes longer but is safer and you'll get there eventually. rather get home later than not at all.

Forecast is exactly that - a forecast, conditions can change quickly - keep your eyes open and head home if it looks like getting bad.

As paul said it really depends on your hull.  My last boat a quintrex 4.75 went in some pretty rough weather that wasnt planned but just going slow got me out of trouble, my biggest fear was a wave breaking into the boat with a smaller freeboard.  Any easterly over 10 knots made it a bit uncomfortable offshore in that boat too, a strong offshore wind pushing into a close swell makes it uncomfortable in most boats.

 Might seem obvious but people can be way to keen and be caught out.

It might be ok to have a island to hide behind till it drops but with no protection just don't do it.

Having said that on the south coast 15 - 20 is doable is most deep sea fishos have big cats.

 If heading cross wind/swell you need to be on your game, if the boat starts diving away from a wave/down the face it’s natural to want to pull away or head into the wave. That’s a BIG no no, pull hard to the direction you’re diving to throw the weight to the other side as if you want to catch the wave and I also find backing off the throttle helps. Hopefully that explained it. 

Cheers for the responses some helpful information for sure, just to give you and idea i have 21ft fibreglass, which handles very well in most conditions.

the only thing i do feel a little unconfortable in is a following sea, sometimes the wave has control of you.

i like to travel just faster than the wave, makes for a smooth and controllable ride and always drive to where the weather is nicer, keep one hand on the wheel and one on the throttle so you can react if it ever gets unpredicatable.

I got a good run last weekend and found the appropriate conditions i will NOT be taking my boat out in again. gotta get that Haines Hunter 760R....

I was always taught in a heavy following sea steer 10-15 degrees either side of the direction of the sea, you have better control and your hull predictably will only try to fall  one way down the wave as opposed to a sea directly behind where each wave will decide at random wether she falls either left or right.

Not too much the case for our seas/chop but  if crossing a bar, rivermouth or a breaking swell area match the speed and always ride the back of a wave for maximum control never ride the trough and never "surf"

Each boats different, drive the boat to what feels good for the hull, if i can't get that sweet spot i shouldn't be out.... or need a new boat!

some reakon if you go out far enough it calms off, if it dosen't its a long hard road home[behind an island or reef helps] following seas slow and steady,watch for the sideways movement,tuck in behind a ferry etc if you can, be very aware on wind strengh and wind changes,don't be ashamed to head for home if in doult,at least you will fish another day, with all the sinking and deaths and not being in great healh, I wearing a jacket all the time now, at least I'll know where it is and it won't go down with the boat,WATCH FOR SWELLS AROUND REEF AREAS, happy boating

thanks for your feedback brucesta, uncle and reefmonkey, some good reading.

appreciate gents.

It might be a bit over cautious but i carry 2 sand anchors, 2 reef anchors and a couple of hundred metres of rope. When i first started boating beginning of last summer i had just the one sand anchor and reef anchor and 100m of rope and thought thats all i'll need. We lost the reef anchor and most of the rope (had to cut it) first trip out deep. Coming back to hillarys I started thinking - Shit if the motor stops we gonna drift straight onto the reef in this strong SW wind and big swell - scary thought. I also carry three extra bilge pumps (even I'll admit thats over kill) but they get blocked easily with old fish guts, scales seaweed etc. Also I carry one of those electric jump starter packs for if the battery dies - also you can run the bilge off of it if the motor just wont start. Ive also lent it twice to other boaters who have needed it out there to start their motors - very handy to have. We go out to the FADs alot, its too deep to anchor so we carry two large drift anchors incase motor dies and seas pick up - you can deploy them both to keep the bow into the waves while waiting to be rescued. The boat came with an older 27meg radio and fixed antenna. I could get reception at the FADs but it was faint. I bought a new GME 1.8m detachable antenna and it worked better but when i was standing up in the hatch to anchor a wave bumped me sideways, I just leant a bit on the antenna and the fucken thing snapped off where the thin brass screw holds it onto the deck mount - I just caught it before it went over the side forever which would have left us out there with no radio so be careful of that if you've got one of those - i wouldnt have bought it if i knew it was so weak so I now carry the old antenna always as backup. Take "shit loads" more fuel than you need and many other boaters told me I should fit a fuel water separator so i did that. Im only relatively new to boating so i hope some of this is useful to you oh and one more thing - Take shit loads more beer than you think youll need as well!  

I LEAVE THE BEER AT HOME THOUGH

great tips beer oclock - thanks for that, i do like to extra cautious myself, my second bilge pump is my bucket :)

i like the idea of electric pump starter packs - guessing you can get them anywhere.

oh and dont worry about the beer - i always make sure im set for atleast 2 days haha.

also got a day off on friday and really want to head out just past rotto - swell is looking a little up being 2 - 3 metres, willy weather saying 2.2 - 1.9, seabreeze 2.9 and falling. with there being no wind im guessing it will be just a bit lumpy - would you go out?

fish on the n/end of rotto,but will check closer to the day

yeah i  go out from hillarys so i usually go the north end uncle, picked up another spot just behind rotto the other day aswell.

trying to find a decky at the moment though - everyone is working.

If you pick up a wave and start surfing down the face DO NOT back the throttle off. That will drop the nose and around and over you will go. Better to get the nose up even if it means giving it a good squirt but once clear of the wave back it off.

For northern waters, forget the 27 meg radio because there is hardly anyone up here who use them. Spend the money and go VHF, there are high level discussions going on to allow rec boaters to use it without a marine radio ops licence.

Never tie you drogue / sea anchor off on the stern of your boat unless you want to learn how to swim in a hurry.

some weeks ago I overstayed,had the radio down so they called the home and then the wife called me, a couple of times they didn't answer my radio call to log off,so used the mobile,cant back of when your on the swell,you lose your ride!!

 one day that broached in the south passage (following sea) at Coral Bay - it was without doubt one the scariest moments I have had - to this day (I wasn't driving) - certainly made the skipper reconsider how he drives. We narrowly avoided going overboard. Was in shock for a bit after that. Jut proved to me how things can go wrong very quickly.  

copped a few big swells 3 to 4 metres, came down and the deakie didn't bend his knees, broken foot,bugger, took him back in thru the north passage,picked up a crewie and went back out, never used the south passage again

 we were in a little pacemaker runabout and on the way out, he got air over the swell - I remember thinking then, that was a brave move. I only managed to stay on board becuase I got hold of some railing on the port side - I sublaxed my shoulder doing it, but managed to stay on board. I cant properly described that feeleing of that violent broach (nearly needed a jock change). He did always use the north passge after that, unless it was flat as tack down south.

 This is the reason I've asked for advice on Kalbarri. I know the previous owner of my boat nearly sunk it by doing exactly the same thing Paully. It cost him 12k worth of dental work as his teeth hit the steering wheel. Reckons the sea was beneath the boat one  second the next it was gone and down it went hard. They were lucky too. I won't take any chances.

Mate I fish out of a 4.65 Fibreglass dinghy and regularly fish 8-9km out,

I personally will not take my boat out in anything over a 2 mtr swell and +10 knots.

As the other guys have said slowing down is the way to go if the wind

has picked up and you have a chop, one thing I do quite often is head

out from the ramp in a south westerly direction as I prefer to have the

wind and swell running behind me then against the side of my boat on the trip back in. I  find its

less wet aswell. I also spend atleast 5 minutes sussing out a spot before I anchor

just to make sure that there are no breaking waves in the area, make sure you put out heaps

of anchor rope out to allow for any larger swells. Agree with Rig on the easterly and short swell, pretty scary when the wind

pushes the ass end of your boat towards the incoming swell.

 Local knowledge is always handy ,reefs,passages ect,ect but at the end of the day each boat will perform different depending on Make and load .Getting out on the water in different conditions is the best way, and learn your boat and it will all fall into place .Advice is that and when it comes to the crunch your not going to be thinking mmmmmmm what was it they said on FW you will have to reley on your own capabilities so get out on the water and feel what your boat is doing ,and always watch the water in front. There is no substitute for experiance . Happy fishing .All that has been said is all good advice