I skipper a 10m blyth work cat, we burn roughly 1.6ltr per engine per mile @ 17-21knts (2000 rpm - 280hp iveco's) so a fairly thirsty boat.
They are good in a head sea, close chop or beam on while underway.
Swell up your ass becomes hard work and the small rudders don't help so in a following sea or at slow speeds it's easier to control on the engines than the helm.
We run between 2000 and 2100 rpm which gives us between 17 and 21kts (tide and weather dependent)
At anchor generally great but can get a bit uncomfortable in a short beam on chop (>1m) only other issue at anchor is the bulbs lift the bow high on larger swells that can cause the anchor to slip on hard ground - but we use loads of chain and warp to overcome this.
As so much of the boat is out of the water and it has very square sides it can be affected by the wind while at anchor and drifting but here in the Bristol channel the tide is normally strong enough to over come this. I think the same can be said for most cats though.
Not everyone gets on with them, so definitely have a look around to see if there is something better suited to what your going to do. For us its great and i love our big blue bus, we normally have between 10 and 12 anglers onboard but everyone still has plenty of space.
if there was just 3-4 of you there are better suited boats that will give you more comfort like the cougers or cheeteh marine cats.
There are plenty of charter boats running blyths, cougers and cheetehs so best bet is to get out on a couple of trips on different boats and see what's best for your mate.
