i dont think it realy matters, its up to the individual . have seen a boat with a play pen on deck for their baby. as long as the child has a life jacket on for safety. get them out there at a young age and used to the water. 

I think it all depends on a couple of things to make the judgement. 

1. Weather conditions

2. Type of fishing, that allows you to still monitor you child.

3. Child has to be able listen to your instructions to stay safe.

4. Having correctly sized PDF.

For number 3, my youngest boy was younger than my daughter for this reason.

Hope this helps.

Disclaimer . I don’t have kids .

Whatever age you see fit is your call , as long as they can wear a life jacket and be supervised at ALL times .

Theres nothing better than getting young children involved in fishing , no doubt about it .

This works well for me , whether it’s applicable or practical to others is debatable. From a safety aspect when kids have been onboard ( nephew , nieces friends kids etc etc ) I like to always run with a minimum of two adults on board before taking on junior passengers with a max of one kid per adult . If stuff turns pear shaped and you need to concentrate on operating the boat, pulling a stuck anchor or even untangling a stack of lines there’s another adult to take care of the kids . This way they should feel safe secure for their adventures on the water . Whether they enjoy themselves is purely up to them ! .

Now back to enjoying a quiet Sunday morning in bed...:) 

 Ive taken my kids as babies on the river and have since taken my eldest boy when he was 3(now 4) on the 3 mile for a fish a couple of times when conditions were A1. Jacket on the whole time and you dont get long before they are bored and want to come in! I wouldnt hesitate taking him to do the pots but only if conditions were glass, if there was any bump he wouldnt be coming.

Mine have all been coming on the boat since birth, since well before birth actually.  My youngest is dead keen to come and do multi day swag on deck trips but I’ve told him he has to be able to swim properly first. 

The flip side is I have had a fishing acquaintance lose his 2 year old son in a boating accident so that heightens the awareness of overnighters. 

Better than sitting in front front of the Xbox though. 

Heaps of good info, thanks guys. My boy is almost three and does listen to me most of the time  so I think now is the time. Going to be a proud moment having him on the water for the first time 

 Having youngsters on the boat is great but pulling pots may not be the best way to introduce them to boating. Getting him used to the boat and conditions should be done when you can give your undivided attention. No good that he wears a life jacket if he is tangled in a pot rope when it goes over.

I've taken all three of my kids out and started to take my youngest (just turned 4) out with just me at age 3 but only in the Peel Inlet and Geo Bay so far as she isn't old enough to brace herself if it gets bumpy in the passenger seat and I don't want her sitting on the bench seat alone while we are driving at speed. She loves it but her older brothers get bored pretty quickly so the key is to take lots of snacks out to stop them whinging.

I treat it like I am solo fishing so along with her safety gear I also wear my lifejacket with my PLB and VHF attached to it.

Infant Appropriate Life Jackets. According to the U.S. Coast Guard's Office of Boating Safety, babies should not travel on a boat — including rowboats, kayaks, motorboats, and sailboats — until they are at the appropriate weight to wear an approved personal flotation device (PFD).

 Can he swim?
At that age (if not already) Id be getting him lessons, boating or not.

A life skill that will save him whether its a pool, drain, goldfish pond, bucket.

There is no too young for that. 

Certainly mine I wouldnt take them to the islands until they could jump off the front and swim to the back and climb up the ladder unaided.

Of course any such boating decision hinges not on "done it for years with no problem", its when it goes wrong.

Rough weather, seasick, another emergency that takes your attention like breakdown, erratic boat pilots etc

 My two have been on the boat since they were three weeks old though my first time out with just myself and one of them was just before my daughter turned three. Life jacket on with lots of snacks. Just played in the sound and thanks to Alcoa pumping out some toxic shit that day, she hates venturing down that way.