Axopar 37 - Handling at 15-20 knots

[CURIOUS2]

Thinking of getting one of these. But don’t want to necessarily fly around at thirty or forty knots. Are they usable in the twelve to twenty knot range. Also how are they in a choppy sea, does the hull slam. Thanks …..

 

[julians]

I dont have an axopar 37, but do have a 2021 axopar 28 T-top , I would imagine that they handle similarly.

Its perfectly fine/usable at lower speeds, in fact its pretty much the same as any other planing boat would be at those speeds, but like any other planing boat its better,and more fuel efficient, at a higher speed if the sea conditions allow it. The axopar 28 seems happiest at between 25 and 30 knots, and can handle quite a range of sea states at this speed.

I think if you are primarily wanting to travel more slowly then a different boat may be a better choice , but then I'd say that about any fast ish planing boat really, why buy a boat that can do 45-50 knots knots and will cruise at 30 if you only really want to cruise at 15.

 

[petem]

Its perfectly fine/usable at lower speeds, in fact its pretty much the same as any other planing boat would be at those speeds, but like any other planing boat its better,and more fuel efficient, at a higher speed if the sea conditions allow it. The axopar 28 seems happiest at between 25 and 30 knots, and can handle quite a range of sea states at this speed.

That might be case once over the hump but I doubt after that it gets more efficient the faster you go.

At what speed do you reckon you get on the plane?

I'd be interested to see the fuel burn graphs for Axopars as it may be the case that it's running quite efficiently at the high teens knots.

 

[julians]

That might be case once over the hump but I doubt after that it gets more efficient the faster you go.

At what speed do you reckon you get on the plane?

I'd be interested to see the fuel burn graphs for Axopars as it may be the case that it's running quite efficiently at the high teens knots.

I didnt mean to say/imply that efficiency keeps improving the faster you go, just that the most efficient speed is quite a lot higher than 15 knots.

Heres the numbers from a test of 2019 28 cabin with 2 x 200 hp merc outboards. More efficient at 27 knots than 20 or 13 knots . looks like efficiency peaks somewhere between 27 and 33 knots - which backs up what I feel when driving , that sort of speed is definitely the sweet spot.

Not sure what speed it planes at, but its quite low (going to guess at around 12-15 knots) because the twin stepped hull gives quite a lot of stern lift and keeps the angle of attack very flat when getting over the hump - there is very little bow rise.

Stepped hulls are interesting when all you've experienced is a traditional planing deep v hull, they stay very flat during the acceleration phase, with the boat seeming to just rise out of the water but staying level . Engine trim and trim tabs dont have as much effect on the hulls angle of attack as they have done on all other normal deep v hulls I've driven.

RPM	MPH	KNOTS	GPH	MPG	NMPG	STAT. MILE	NM	DBA
600	3.2	2.7	1.2	2.6	2.3	161	139.7	52
1000	5.3	4.6	2.1	2.5	2.2	154	134.3	59
1500	7.7	6.7	3.6	2.2	1.9	132	114.7	65
2000	9.3	8	6	1.6	1.4	95	82.7	65
2500	15.3	13.3	8.1	1.9	1.6	115	100.2	74
3000	23.3	20.2	10.4	2.2	2	137	119.5	76
3500	31	26.9	13.7	2.3	2	138	120.2	77
4000	38.1	33.1	17.8	2.1	1.9	131	114.1	79
4500	44.1	38.3	22.5	2	1.7	120	104.2	81
5000	49.6	43.1	30.6	1.6	1.4	99	86.3	82
5500	55.5	48.3	34.8	1.6	1.4	98	85	82
5700	55.9	48.6	35.5	1.6	1.4	96	83.8	83

 

[petem]

Cool. So the boat would appear to be OK at the higher end of the OP's desired speed range but not the lower end.

Kudos to you for posting a table !

 

[julians]

Cool. So the boat would appear to be OK at the higher end of the OP's desired speed range but not the lower end.

Kudos to you for posting a table !

maybe the 37 has a sweet spot at a slightly higher speed range than the 28? that would sound logical to me.

But ignoring fuel efficiency, in terms of handling it handles fine at lower speeds.

 

[Portofino]

Difficult I know but the best way to satisfy your curiosity is the test drive one .
Hoping the sea state meets your requirements to find out were it’s slamming ( if any ? ) threshold is .

I was caught out once when in the market , a boat that ticked a lot of boxes but slammed like hell , or slammed far to low speed in what we thought were nothing waves .
No review , mag mentioned this .I did not have the benefit of reaching out to existing owners ….so had to see for myself.

Other stuff noise , wind buffering at the helm , spray etc etc .

My Porto 35 nice as it was used to throw spray up too much .The bulbous fwd sections ( hull int vol ++) use to direct the airflow up and overthe hull directly into the face of the helm .No biggie it’s just a PITA getting sea salt on your rayban s = smears up .
Use to drive me nuts .
No one ever mentioned this in any mag review .

It slammed as well far too much FWIW for my liking and forces us to drop it off the plane under 16 knots too often .
Suppose the answer was “ don’t take out “ but often in the SoF the wind gets up in the afternoon and you have to return .
Also after a while travel around the coast and when on holiday have to get back to base to catch the flight home .

It always NOW amazes me at boat shows and what folks tell me on here that seakeeping seems to be a taboo subject .
They would rather buy a boat based on its fridge or griddle or something like headroom in the mid cabin .

I know I am in a minority to place seakeeping up there at the top of the list .

Looks like I found another .

 

[Corona Mia]

Thinking of getting one of these. But don’t want to necessarily fly around at thirty or forty knots. Are they usable in the twelve to twenty knot range. Also how are they in a choppy sea, does the hull slam. Thanks …..

I think a lot depends on what sort of sea you are going to be in.

Most boats will handle happily between displacement speed and planning speed in calm waters, but that transition speed between displacement and planning can be very uncomfortable………even in typical Mediterranean afternoon chop!

My 34ft Sessa fully planes around 18 knots. (It’s a heavier boat with inboards and not a stepped hull)
But if we hit a bigger wave at that speed it’s struggling…..unless you quickly hit some more power.
If we’re running at 20 knots+ it’s not a problem.

Every boat is different, but (for us) running between 10 and 20 knots for us is a pain……unless fairly calm. ?

 

[julians]

Also how are they in a choppy sea, does the hull slam. Thanks

Didn't see this question ....

Everything will slam if going fast enough in a rough enough sea, so you really need need to try one and find out whether it meets your requirements.

But , the 28 is the least slammy boat I've been out in, if you can keep it running level it won't slam even in some quite heavy seas.

if you take off squiffy and it lands on one side of the hull it will obviously slam because you're landing on one side of the vee.

Where you have to be slightly careful ,and only slightly, is in a large following sea where it can be easier to stuff the bow into the back of the next wave,. Because of the shape of the bow (ie it doesn't flare out), the bow doesn't try to naturally lift itself as it sinks into the wave,so it can be easier to stuff it. Combined with the fact that the stepped hull is less sensitive to engine trim can make it slightly difficult to keep the bow up. It's not a big deal just a characteristic of that kind of hull, but it's something to be aware of.

They are very capable boats. Are there other boats just as capable? Of course there are,but axopars are right up there in terms of ability to keep running at speed when others slow down.

Ignore the magazine review hype though, if you believe them you'd think it was the best boat on the planet, go and try one and see what you think.

Theyre not perfect , the various tanks (fuel and water) are too small, the dealer I bought from is attrocious ( I suspect they get away with it because right now they're selling like hot cakes), the driving position on the 28 t top at least could be better, plus a few other minor grumbles.

 

[CURIOUS2]

Many thanks for all your insights, very helpful.