New to Paddleboarding - Weight Limit Question

Hi I want to buy a iSUP and I think I want to go for the Redpaddle 10ft 8 inch Ride 2020, however my main concern is that the reccomended max weight is 120kg. I currently weigh 130kg.
The shop owner advised that this wouldn’t have much effect if only 10 kg over, is this true? Will I be okay at that weight? or will it sink and affect performance too much.

I plan to lose weight but don’t want to buy an expensive board and then have to wait 3 months until I’m below 120.

Any help would be appreciated - thanks!

Here is what one manufacturer says on this subject: https://www.islesurfandsup.com/sup-101/paddle-board-size-and-weight-chart/

In addition to this, the heavier you are as compared to the rated capacity, the less stable it is likely to feel.

I am not a paddleboard expert, but I personally would go for a board that is rated above my weight.

The dealer is probably correct, that board has a huge amount of volume. There are two concerns about being above the weight limit, the first is stability as Peter mentioned above, the second is how long can the seams support that much weight/internal pressure. You are just a bit over the engineers estimates so it may be OK. I’m not familiar with large volume SUPs but you might look for a longer SUP that would support more weight. The other options is if you can try one out. I do know that large people do not find standing on a narrow easy paddling SUP an easy thing to do, best advice is to buy where you can try out the board.