i suppose another way of looking at the amount useable floor space in a small sib is if you compare it with the amount of room of an average bath tub ,a boat say 9 foot long will only have an inside length of about 7foot taking into consideration the tube diameter and the sponsons protuding past the transom and the same for the beam or width ,
We were looking at something like 2.7/2.8 to start with but as soon as we saw some boats up close we realised that 3m+ was going to be best..this is for 2 adults mainly but occasionally an extra 1 or 2 passengers.
We've got a Howave (Honda) 3.2m & definately glad we went larger..
We have a 3.2m Zodiac with wooden floor. Used it for the past two years on the sea with a max of two adults and two 12/14 yr old children.... just for short distances. We have no seating to keep the max floor area and we all sit on the tubes. It is unable to plane with it's 9.8hp tohatsu with this load and in anything of a chop we get wet backsides from waves slopping up the tubes.
Drop down to one adult and one or two children and it's a different boat planing up to 19mph and feeling very safe.
It's our second boat but if it was our main one and needed to carry four all the time I'd look for a 3.8m with 20hp or more.
I have a 310 rib and its just too small for four people to adults to kids 8 & 11 get the 350 rib aquillis brand you will be glad you did also the south african bloke is right put about 5 more hp in a 2 stroke more than its rated for most are underpowered
