Don't repair. No matter what you do you will create weak points, it's not worth it. The only time I would consider a repair is if I don't have a spare and want to continue a regatta.

In my experience the cost of shipping vastly outprice the price of material for long items like a bare spin pole. If you want a spare pole, just buy two. And use this opportunity to get other spares shipped to you in the same long box.

Don't forget to ask your fellow clubmates if they need anything as well, we've been doing it with carbon tiller extensions, when bought in bulk 3 meter long bare tubes they are really cheap. Add a golf grip at one end, a connector at the other and make spares for all your mates...