Zodiac FC470 scuba set up

Lachlan · 07 December 2019, 11:07

If you could set up a brand new zodiac FC470 for scuba diving, what would you do and why?

Long shaft or short shaft?
40hp, 50hp, 55hp, 2 x 30hp?
Floor type?
Any other options I’m missing?

I have the opportunity to get a FC470 short shaft with a mercury 40hp for a reasonable price. I want to understand pros and cons and come up with a set up that works.

I’m looking to use the boat for scuba diving primarily. Plan is 4 divers so the boat is never left unattended. With full gear on I’m approx 150kg so 600kg in passengers. If the divers can all have another tank, approx another 100kg, awesome but not essential. Wont be going further than 2kms off shore. Don’t have to go fast but certainly need to get up on the plane and be able to get out of trouble.

Thanks in advance for your help! Appreciate all suggestions!

charliee · 07 December 2019, 11:43

Is an FC 470 a SIB?
It sounds very small for 4 divers let alone with extra cylinders!

GuyC · 07 December 2019, 20:19

http://www.rib.net/forum/f50/fc470-d...ons-57458.html

Welcome to the forum.

Jojosrib · 08 December 2019, 02:02

Quote:

Originally Posted by Lachlan

If you could set up a brand new zodiac FC470 for scuba diving, what would you do and why?

Long shaft or short shaft?
40hp, 50hp, 55hp, 2 x 30hp?
Floor type?
Any other options I’m missing?

I have the opportunity to get a FC470 short shaft with a mercury 40hp for a reasonable price. I want to understand pros and cons and come up with a set up that works.

I’m looking to use the boat for scuba diving primarily. Plan is 4 divers so the boat is never left unattended. With full gear on I’m approx 150kg so 600kg in passengers. If the divers can all have another tank, approx another 100kg, awesome but not essential. Wont be going further than 2kms off shore. Don’t have to go fast but certainly need to get up on the plane and be able to get out of trouble.

Thanks in advance for your help! Appreciate all suggestions!

I have had a couple of boats that length that I’ve used for diving. To be honest it will be really tight on space with what you want to do. If it’s just 2 k offshore and diving only I’d keep it really simple and run an open deck with a tiller steer. You can lay the tanks flat on the deck setup with BCD’s in foam holders.

Lachlan · 08 December 2019, 05:47

Quote:

Originally Posted by Jojosrib

I have had a couple of boats that length that I’ve used for diving. To be honest it will be really tight on space with what you want to do. If it’s just 2 k offshore and diving only I’d keep it really simple and run an open deck with a tiller steer. You can lay the tanks flat on the deck setup with BCD’s in foam holders.

Thanks mate - that what was I was thinking too. The vast majority of the dive sites I want to access are within 1km of a boat ramp or even a beach.

Any thoughts on engine size?

I'm leaning towards a short shaft 50 hp Yamaha with a hydrofoil. Doesn't seem to be a massive price difference between the 40 hp and the 50 hp engines in my area.

jeffstevens763@g · 08 December 2019, 16:09

Go 50 hp bit in reserve then

diver 1 · 08 December 2019, 16:20

You'll be surprised how soon you run out of space / power and capacity when using a small rib for scuba. My first rib was a 4.something metre humber with a 40HP Yam on the back. With 2 people it was a great, fast, fun little rib. However on our first voyage we put 2 sets of scuba gear on it, 3 blokes and we couldn't get above 7 knots. It was useless. Sat very low at the stern when loaded and swamped incredibly easily in any swell. I now have a 5.85m Ribcraft with 140HP and consider it just about right for 4 divers and 1 crew on a regular basis, perhaps more divers on rare exceptions when we're not going far. All this is based on very simple single cylinder scuba set ups with no added kit.

Jojosrib · 08 December 2019, 19:17

Quote:

Originally Posted by Lachlan

Thanks mate - that what was I was thinking too. The vast majority of the dive sites I want to access are within 1km of a boat ramp or even a beach.

Any thoughts on engine size?

I'm leaning towards a short shaft 50 hp Yamaha with a hydrofoil. Doesn't seem to be a massive price difference between the 40 hp and the 50 hp engines in my area.

I would go bigger if there is little difference in price. That said, we ran a 30 hp 2 stroke on a 4.9 rib. It was not fast but did a job. If the weather was right we’d take 4 divers for 2 up 2 down. The beauty of the open deck was the available space and simplicity. Super easy to manage and cost effective. We never took spare tanks, I thinks this would have pushed to hard. We also ran 4 fishermen on this set up quite comfortably with a fish bin in the middle. But this was always an inshore very nice day only rig. Not sure you’ll need a hydrofoil. I would try first.

Jojosrib · 08 December 2019, 20:25

Quote:

Originally Posted by diver 1

You'll be surprised how soon you run out of space / power and capacity when using a small rib for scuba. My first rib was a 4.something metre humber with a 40HP Yam on the back. With 2 people it was a great, fast, fun little rib. However on our first voyage we put 2 sets of scuba gear on it, 3 blokes and we couldn't get above 7 knots. It was useless. Sat very low at the stern when loaded and swamped incredibly easily in any swell. I now have a 5.85m Ribcraft with 140HP and consider it just about right for 4 divers and 1 crew on a regular basis, perhaps more divers on rare exceptions when we're not going far. All this is based on very simple single cylinder scuba set ups with no added kit.

Hi, Diver 1

Out of interest how do you set up your rig for diving?

Squid Boat · 08 December 2019, 20:29

50 hp tiller and cargo net in case gear comes loose. I carry a lot of weight with a similar boat, no problem.

Cheers

Lachlan · 09 December 2019, 00:29

Quote:

Originally Posted by diver 1

You'll be surprised how soon you run out of space / power and capacity when using a small rib for scuba. My first rib was a 4.something metre humber with a 40HP Yam on the back. With 2 people it was a great, fast, fun little rib. However on our first voyage we put 2 sets of scuba gear on it, 3 blokes and we couldn't get above 7 knots. It was useless. Sat very low at the stern when loaded and swamped incredibly easily in any swell. I now have a 5.85m Ribcraft with 140HP and consider it just about right for 4 divers and 1 crew on a regular basis, perhaps more divers on rare exceptions when we're not going far. All this is based on very simple single cylinder scuba set ups with no added kit.

I've read a bit about this and I'm a little nervous of that happening too. I've checked out some other boats that have a max payload of around 900kg and I just don't think it will cut it. 4 divers with all there gear is approx 600kg + safety equipment + motor + fuel....

The FC470 can take 1250 kg though so I think it will be okay.

Do you happen to remember what the max payload of your old boat was?

Lachlan · 09 December 2019, 00:31

Quote:

Originally Posted by Jojosrib

we’d take 4 divers for 2 up 2 down. The beauty of the open deck was the available space and simplicity. Super easy to manage and cost effective.

That's the dream!!!

Your 4.9 rib: reckon you could take the extra tanks if you had a bigger outboard? What was its max payload?

Jojosrib · 09 December 2019, 23:59

Your 4.9 rib: reckon you could take the extra tanks if you had a bigger outboard? What was its max payload?[/QUOTE]

It was a while ago so can’t remember the payload. Could it take extra tanks?. Probably......would I give it a go?......No......At sea......even inshore on a great day and forecast.....I want a bit left in my pocket...600kg is plenty for a boat of this size...