My old boat was a 5.3 meter Ali with a 90 hp four stroke we fished much further out than 40 m including the FAD's .

if the winds turns on you it can be a long ,wet and bumpy ride home . 

But as the old saying goes 

Calm seas dont make good sailors 

I remember seeing an article of a bloke with the same or similar size Haines that drove it from Darwin to Japan. Pretty extreme but speaks volumes for the sea worthiness of these vessels. Be sensible with the weather and safety gear and you should be fine.

 Hans tholstrup. Hang seen anything from him for a few years now.

I've had my 5.3 Haines to the Montes a few times. Very seaworthy little boat but skipper experience is more important.

 Hans also did the lap of oz in a dinghy with a tiller 50.

I was prob only 7 or 8 when he scooted into Augusta.

I can remember my old man being pretty blown away.

Hans circumnavigated Australia in a 17ft Carribean Cougar with a 80hp Mercury 2 stroke.

I have an old Carribean Cougar sitting in my back yard and while it's a great handling boat for its size, I don't think I would want to drive it around Australia.

 Knowing the waters is just as important as the boat capabilities. Have to know where all the real dodgy bits are and stay well clear. May take a little longer to get out and back, but at least you get there safely.

With a smaller boat there is a smaller judgement of error.  

 You'll be fine mate. Pick your days and trust your instinct, if you feel uncomfortable then don't go. Anything over 10 knots is an inshore job, under 10 is worth heading out and on the rare occasion that its a glass off then that's your cue. Also a good gps and sounder will make life much easier too.

 Haines is a great brand.  But as skipper you have to know your capabilities as well if not more than your boats.  I have a 5m alloy boat that i wouldn't hesitate taking out to the fads in the right conditions. But I have confidence in getting back safely if it turns to shit.  Know your boats capabilities.  Know your own.  And first time,  arrange to go with a second boat, who already has the experience.  I have 40 years experience on the water, two years ago I did the passage from denham to steep point for the first time...  in company with a boat that had done it several times before.  Prior experience is priceless.   Experienced boaties respect skippers who know their limitations and ask questions before going out. And they're the ones who take the time to help.

 I have an old swift craft explorer With a 90 2stroke. I have been out to the continental shelf on a good day. If your a bit nervous this is a good thing, it's people that have no fear that get into strife IMO. Theres a good community on this site maybe when you next plan on going for a venture out that far ask if you could tag along with another boat, gives you more experience and confidence with the added safety of knowing there's another boat close by that can give you a hand. If you want to follow me out after the ban for a morning session send me a PM before you go, I like to get out at least 2 times a month, provided I've earnt enough browny points with the boss;)