Jet Tenders/RIBS
As to some that people might have had in the past, many were just ribs with Yamaha waverunner engines and drives and gave a good bit of trouble. Novurania has some high end jet tenders, excellent. Nautica was not nearly equal. Then there are some brands like Carbon Craft and Castoldi that are quality but extremely expensive. Avon made three models and we have one of them that came relabeled on a Riva. They and Williams were very comparable. There have been companies like Ribjet to do very little and Aquascan hasn't done much more. Again, some have used the Yamaha units which have been more problematic. Agilis is not sold in the US.
Now there is one new player worth considering. AB has added 7 jet models and as they're a dependable RIB producer, I'd expect great success. They use Rotax now as well.
When we got our first Williams gas models (we also have diesel), they were Weber engines (now Textron). The switch to Rotax was fairly recent, first in certain models, then expanded. We were concerned but after experience with them are not so. I think it's more along the lines of Rotax as used in boats like Chaparral rather than Sea Doo. So far have performed well.
We love jet tenders. All but the one Avon we have are Williams. We've been very pleased with them. Safety is a factor, although not so much in an area the water is too cold to enter. Shallow water usage is sometimes overstated. I don't recommend under 2' of water as depending on the bottom, you're more inclined to suck in debris, whether plant or sand. Just because you can go shallower, doesn't mean it's wise to do regularly.
We like the balance of having the engine inboard and that does help with ride and performance. We love the performance. 40 knots is nice and the ability to carry a load and cruise well at 20-25 knots to explore is even nicer. With the hours we put on, maintenance is less than an outboard. Also, flushing systems are built in.
Then the biggest advantage perhaps is size. A 14' jet rib will take the space of a 12' outboard rib as you have to add the motor and it's space. So length is all within the RIB. Then there is height. Without an outboard they take up very little space. On your bridge they sit low. On your platform, they sit low. And where Williams has built their market in Europe is the proliferation of garages. Sure is nice to just open the door and roll it out into the water. Yet, inside your hull, you barely notice as they sit neatly above anything inside in more configurations.
We carried a Williams 385, now 395 fits, on a Sunseeker Manhattan 65's swim platform. The 395 is 12'8". The biggest outboard version you could fit would be 11' and the 395 has the interior space of a 14' outboard rib, and seats 6, so basically outboard leads to 3' less if stored in that way. On a 52' Riva with a garage one can get a 10'9" Jet seating 4. That boat has no way of carrying an outboard. On our AB we were able to get two ribs instead of a rib and jet ski.
The Williams ride is also great as they have deep v's for their size. We've done a comparison to similar sized Boston Whalers on the west coast of FL with the Whaler dealer and in rough water and the Williams very much outperformed the Whaler.
Negatives are:
-initial cost
-fuel capacities are low vs usage at speed
-you still must be respectful of shallow water and debris and not assume a jet is fine in it. Similarly if beaching, you must cut it off early as you'd lift an outboard. Don't run it into sand.
With ourselves and those close to us, a total of something like 12 Jet Ribs and we're sold. Sold on Williams, although not dismissing AB by any means.