Hi folks and thanks for adding me to forum. Have a new smart wave 3500 and new Suzuki 15 hp 4 st. Ls. I have trimmed engine at various positions and boat will not plane with just me in it . I weigh 70 kg and have the motor trimmed in to the stern at the last hole. Do I need to add weight in the bow /change prop or what. Any advive would be very welcome ...pulling my hair out at this stage and have read this boats review with 2 aboard and same set up as mine where it planed no problem.

is it brand a new hull? they have been having problems with their molds blowing out check to see if the hull lines are straight. 15hp should definitely get on the plane ive got a 30hp on mine. chuck up some pictures,

Under powered.. will sit bow up and hard to get to plain..
 See comments on power from the guys above.

 Also the recommended hp rating for general use by the manufactures IS 30 hp

NEVER .. never go the bottom spec power on any boat..
 unless just want something to get from shore to your main moored launch.. which it sounds like is what you have powered for.

motor too low.. thats like dropping another couple ppl  or pour load of cement in the boat..
Your problem is the bow getting over the bow wave.. its like driving a under powered car up a steep hill.. you really think dropping a extra weight in the car would help?
 Stay well away from those who give such .. yep BS... advice.

Planing hulls are powered to weight .. not like displacement hulls that are length..

 A 4 blade prop with a lot of rake will lever the bow down and the stern up IF reasonable power AND engine cavitation plate set correct height at normal to fast cruise.

The correct prop, for the end use of the hull

 The dealer should have sorted all this stuff for you.

 but the chances are the sales person wouldnt know much more than than a motor boat has a motor ..

Maybe too obvious, but it sounds like you have a long shaft motor on a short shaft transom.

Thanks lads for replies. Supplier specified long shaft. Tiller extension will be next thing to try. Also will look at changing to 20hp or 25 hp if dealer gives good deal on the 15hp .

Thanks for the info Kandrew

Still waiting to hear back from manufacturer.
 Gallergers are basically closed till the 6th Jan , with only a basic staff on till then..

Reason I went with this setup was after reading the review here

 Reality Check
 We had a review journalist at our car club meet a while back.. a close friend of several members.
 Off the record.. all reviews are positive even when they cant be..If actually say what the mean then the journo then doesnt get further offers to review and becomes unemployed.
 Add to that , with boats, often when crunch their numbers , boats are propped  and carry very light loads that give results very different to joe publics loaded boat  propped to that weight..
 I hate it (heart breaking) when so often ppl come to me with their new rig " why doesnt it go like the sea trial/ review.. can I re prop so it will?
 you cant re prop to increase HP

report said it planed easily and got 20 knots. WTF is all that about?.
Crunch numbers, keep in mind I dont have much info on this hull in my data base for accurate constant number.
Works out that the TOTAL gross weight on the water ppl everything) will be 350 /450kg
 I have no idea if that would be close to reality

If the prop/ leg is too deep, even say 2" thats sort of the equivalent to and extra adult.. and a small boat that a huge difference.

I note yours is a 4 stroke, maybe it lacks the initial grunt to take it over the bow wave,

 put this statement into perspective.

 Im starting to see this sort of thing recently as more $s engines on small boats become more common.
 By nature a $S has significantly less power in low and mid low rpm ranges.. hence why in General they have 10 to 15% more WoT rpm power than advertised, lifting the whole rpm poer curve to match 2S.
 Now add say tops 15%% onto a small 15hp thats 17/18 hp .. not very significant.
 Add only 10hp  7% onto a 140hp on a 5.5m 1250kg boat and the difference in hull performance is very noticeable.. to over powered.

things that will help to get over that bow wave
Tiller extension will be next thing to try
 A prop with more rake.
 And last which will remove any manufactures warrantees... a permatrim.

The Smartwave should indeed do just fine with a 15hp 2S one or two up. I put five on mine 2adults 3 small kids and it popped up on the plane easy as. I later put a 20hp 4S suzuki Df20a on it and it was absolutely fine, except when I had a lot of weight on.