Gusty, lovely sunny afternoon
Wind would increase considerably in the afternoon.
Upon arrival, the wind didn't seem to be strong yet. 8.3 looked the needed size. There were occasionally hard gusts, so started with 7.3.

S-Type 7.3 with iSonic 117 and SL-X 43cm
Waiting for the gusts to get planing. Once planing, I could usually plane entire run, and then after the jibe I had to wait for the next gusts.
Wind soon increased, I could plane easier and longer, also planing jibes got easier. Until the wind turned on. The wind got a lot stronger. The 7.3 trimmed over max: it was just doable. My competition experience helped a lot. Everywhere you saw surfers crashing in the strong gusts, many surfers sailed with sail open. Time for smaller kit, or finally give my SL-X 39cm a try.

S-Type 7.3 with iSonic 117 and SL-X 39cm
Wind increased more. The 39cm clearly better than the 43cm. With the 43cm upwind was too easily and downwind was not really pleasant. With the 39cm, the board clearly has more control downwind. Very tiring sailing with so many wind. Time for easier kit.

Banzai 6.0 with JP FSW 102 and MFC 29cm
Doubted between 5.3 and 6.0. 5.3 seemed so small compared to the 7.3. Direct planing: full power. In the middle even overpowered: pushing with your front hand. Sail over max trimmed and then it was often doable. Board has a lot of control. Nice chop hopping. In flatter water, I could let the board run loosely and then planing jibes.
Sailed until the 6.0 really became too big. I didn't feel like rigging a smaller sail.

Nice sailing, but very gusty today.

Kabbelaarsbank

15:00 2 hour Wind: SW
Board: Starboard iSonic 117 - Sonntag SL-X 43cm
Sail: North S-Type SL 7.3 - North Platinum(11) 460 - AL360 E3 Carbon 200-260
  Gusty, in the gusts very good, in the harder gusts the board ran wonderfully free. 7.3 was the best size, in the harder gusts not too big but in the wind holes sometimes too small. Although then everyone stood still and 8.3 would probably have been too small to. Control very well, upwind in the gusts very well.
17:00 0.5 hour Wind: SW
Board: Starboard iSonic 117 - Sonntag SL-X 39cm
Sail: North S-Type SL 7.3 - North Platinum(11) 460 - AL360 E3 Carbon 200-260
  Sailed the SL-X 39cm for the first time. Wind was much stronger, the 39cm is clearly the right choice. Board still runs easily upwind and control is slightly better. Sail really became too big in the gusts. Almost all gybes were planing gybes.
17:45 1 hour Wind: SW
Board: JP Freestyle Wave 102 Pro - MFC Freewave 29cm
Sail: Goya Banzai Pro 6.0 - Goya Hunderd Pro 430 - AL360 E3 Carbon 160-220
  Doubted between 5.3 and 6.0, took the 6.0 taken, step from 7.3 to 5.3 seemed too big. Wrong choice.
In the gusts the 6.0 was overpowered, even with over max trim, it only just doable in the hardest gusts.
Board had good control, didn't feel too big and didn't fly. Great jumping. Almost all gybes were planing: more than enough power in the sail.